The Orb-Weaving Spiders of Canada and Alaska: Uloboridae, Tetragnathidae, Araneidae, Theridiosomatidae) the Insects and Arachnids of Canada

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THE INSECTS AND ARACHNIDS OF CANADA PART 23 The Orb-Weaving Spiders of Canada and Alaska Araneae: Uloboridae, Tetragnathidae, Araneidae, Theridiosomatidae Charles D. Dondale and James H. Redner Eastern Cereal and Oilseed Research Centre Ottawa, Ontario Pierre Paquin Département de sciences biologiques, Université de Montréal Montréal, Québec Herbert W. Levi Museum of Comparative Zoology, Harvard University Cambridge, Massachusetts

NRC Research Press Ottawa 2003

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© 2003 National Research Council of Canada All rights reserved. No part of this publication may be reproduced in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada. Printed in Canada on acid-free paper. ISBN 0-660-18898-8 Electronic ISBN 0-660-19260-8 ISSN 0706-7313 NRC No. 44466

National Library of Canada cataloguing in publication data Dondale, Charles D. The Orb-Weaving Spiders of Canada and Alaska: Araneae: Uloboridae, Tetragnathidae, Araneidae, Theridiosomatidae (The Insects and Arachnids of Canada, 0706-7313; pt. 23) Co-published by Agriculture and Agri-Food Canada, Research Branch. Issued by the National Research Council of Canada. Includes bibliographical references and an index. ISBN 0-660-18898-8 1. 3. 5. 7.

Orb weavers — Canada Spiders — Canada Araneidae Uloboridae

I. II. III. IV. V.

2. 4. 6. 8.

Orb weavers — Alaska Spiders — Alaska Tetragnathidae Theridiosomatidae

Redner, James H. Canada. Agriculture and Agri-Food Canada. Research Branch. National Research Council Canada. Title. Series: Insects and Arachnids of Canada.

QL458.42A73D65 2003

595.4’4

C2003-980111-X

NRC Monograph Publishing Program Editor: P.B. Cavers (University of Western Ontario) Editorial Board: H. Alper, OC, FRSC (University of Ottawa); G.L. Baskerville, FRSC (University of British Columbia); W.G.E. Caldwell, OC, FRSC (University of Western Ontario); C.A. Campbell, CM, SOM (Eastern Cereal and Oilseed Research Centre); S. Gubins (Annual Reviews); B. Ladanyi, FRSC (École Polytechnique de Montréal); W.H. Lewis (Washington University); A.W. May, OC (Memorial University of Newfoundland); G.G.E. Scudder, OC, FRSC (University of British Columbia); B.P. Dancik, Editor-in-Chief, NRC Research Press (University of Alberta) Inquiries: Monograph Publishing Program, NRC Research Press, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada. Web site: www.monographs.nrc.ca Correct citation for this publication: Dondale, C.D., J.H. Redner, P. Paquin, and H.W. Levi. 2003. The Insects and Arachnids of Canada. Part 23. The Orb-Weaving Spiders of Canada and Alaska (Araneae: Uloboridae, Tetragnathidae, Araneidae, Theridiosomatidae). NRC Research Press, Ottawa, Ontario, Canada. 371 p.

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The Insects and Arachnids of Canada Part 1.

Collecting, Preparing and Preserving Insects, Mites and Spiders, compiled by J.E.H. Martin, Biosystematics Research Institute, Ottawa, 1977.

Partie 1. Récolte, préparation et conservation des Insectes, des Acariens et des Araignées, comilé par J.E. H. Martin, Institut de recherches biosystématiques, Ottawa, 1983. Part 2.

The Bark Beetles of Canada and Alaska (Coleoptera: Scolytidae), by D.E. Bright, Jr., Biosystematics Research Institute, Ottawa, 1976.

Part 3.

The Aradidae of Canada (Hemiptera: Aradidae), by R. Matsuda, Biosystematics Research Institute, Ottawa, 1977.

Part 4.

The Anthocoridae of Canada and Alaska (Heteroptera: Anthocoridae), by L.A. Kelton, Biosystematics Research Institute, Ottawa, 1978.

Part 5.

The Crab Spiders of Canada and Alaska (Araneae: Philodromidae and Thomisidae), by C.D. Dondale and J.H. Redner, Biosystematics Research Institute, Ottawa, 1978.

Part 6.

The Mosquitoes of Canada (Diptera: Culicidae), by D.M. Wood, P.T. Dang and R.A. Ellis, Biosystematics Research Institute, Ottawa, 1979.

Part 7.

Genera of the Trichoptera of Canada and Adjoining or Adjacent United States, by F. Schmid, Biosystematics Research Institute, Ottawa, 1998.

Partie 7. Genera des Trichoptères du Canada et des États adjacents, par F. Schmid, Institut de recherches biosystématiques, Ottawa, 1980. Part 8.

The Plant Bugs of the Prairie Provinces of Canada (Heteroptera: Miridae), by L.A. Kelton, Biosystematics Research Institute, Ottawa, 1980.

Part 9.

The Sac Spiders of Canada and Alaska (Araneae: Clubionidae and Anyphaenidae), by C.D. Dondale and J.H. Redner, Biosystematics Research Institute, Ottawa, 1982.

Part 10. The Spittlebugs of Canada (Homoptera: Cercopidae), by K.G.A. Hamilton, Biosystematics Research Institute, Ottawa, 1982. Part 11. The Genera of Larval Midges of Canada (Diptera: Chironomidae), by D.R. Oliver and M.E. Roussel, Biosystematics Research Institute, Ottawa, 1983. Part 12. The Families and Subfamilies of Canadian Chalcidoid Wasps (Hymenoptera: Chalcidoidea), by C.M. Yoshimoto, Biosystematics Research Institute, Ottawa, 1984. iii

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Part 13. Carrion Beetles of Canada and Alaska (Coleoptera: Silphidae and Agyrtidae), by R.S. Anderson and S.B. Peck, Biosystematics Research Institute, Ottawa, 1985. Part 14. The Grasshoppers, Crickets, and Related Insects of Canada and Adjacent Regions (Ulonata: Dermaptera, Cheleutoptera, Notoptera, Dictuoptera, Grylloptera, and Orthoptera), by V.R. Vickery and D.K. McE. Kevan, Biosystematics Research Institute, Ottawa, 1986. Part 15. The Metallic Wood-Boring Beetles of Canada and Alaska (Coleoptera: Buprestidae), by D.E. Bright, Biosystematics Research Institute, Ottawa, 1987. Part 16. The Horse Flies and Deer Flies of Canada and Alaska (Diptera: Tabanidae), by H.J. Teskey, Biosystematics Research Institute, Ottawa, 1990. Part 17. The Wolf Spiders, Nurseryweb Spiders, and Lynx Spiders of Canada and Alaska (Araneae: Lycosidae, Pisauridae, and Oxyopidae), by C.D. Dondale and J.H. Redner, Biosystematics Research Centre, Ottawa, 1990. Part 18. The Flower Flies of the Subfamily Syrphinae of Canada, Alaska, and Greenland (Diptera: Syrphidae), by J.R. Vockeroth, Centre for Land and Biological Resources, Research Branch, Ottawa, 1991. Part 19. The Ground Spiders of Alaska and Canada (Araneae: Gnaphosidae), by N.I. Platnick and C.D. Dondale, Centre for Land and Biological Resources, Research Branch, Ottawa, 1992. Part 20. The Genera and Subgenera of the Sawflies of Canada and Alaska (Hymenoptera: Symphyta), by H. Goulet, Centre for Land and Biological Resources, Research Branch, Ottawa 1992. Part 21. The Weevils of Canada and Alaska. Volume 1 (Coleoptera: Curculionoidea, excluding Scolytidae and Curculionidae), by D.E. Bright, Centre for Land and Biological Resources, Research Branch, Agriculture Canada, Ottawa, 1993. Part 22. The Genera of the Aphids of Canada (Homoptera: Aphidoidea and Phylloxeroidea), by R.G. Foottit and W.R. Richards, Research Branch, Agriculture Canada, Ottawa, 1993.

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Table of Contents Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Anatomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Definition of orb-weaving spiders . . . . . . . . . . . . . . . . . . . . . . . . 12 Nature of orb webs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Ecribellate webs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Cribellate webs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Production and uses of silk . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Venoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Habitats and diets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Reproduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Family Uloboridae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Key to genera of Uloboridae . . . . . . . . . . . . . . . . . . . . . . . . . 34 Genus Hyptiotes Walckenaer. . . . . . . . . . . . . . . . . . . . . . . . . 34 Genus Uloborus Latreille . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Family Tetragnathidae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Key to genera of Tetragnathidae . . . . . . . . . . . . . . . . . . . . . . . 46 Genus Glenognatha Simon. . . . . . . . . . . . . . . . . . . . . . . . . . 47 Genus Leucauge White. . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Genus Tetragnatha Latreille . . . . . . . . . . . . . . . . . . . . . . . . . 53 Genus Pachygnatha Sundevall. . . . . . . . . . . . . . . . . . . . . . . . 88 Genus Metellina Chamberlin & Ivie . . . . . . . . . . . . . . . . . . . . 107 Genus Meta C.L. Koch . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Family Araneidae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 Key to genera of Araneidae. . . . . . . . . . . . . . . . . . . . . . . . . 121 Genus Mastophora Holmberg . . . . . . . . . . . . . . . . . . . . . . . 129 Genus Mangora O. Pickard-Cambridge . . . . . . . . . . . . . . . . . . 133 Genus Micrathena Sundevall . . . . . . . . . . . . . . . . . . . . . . . . 141 Genus Gea C.L. Koch. . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 Genus Argiope Audouin . . . . . . . . . . . . . . . . . . . . . . . . . . 153 Genus Cyclosa Menge . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Genus Neoscona Simon. . . . . . . . . . . . . . . . . . . . . . . . . . . 166 Genus Aculepeira Chamberlin & Ivie . . . . . . . . . . . . . . . . . . . 175 Genus Larinioides di Caporiacco. . . . . . . . . . . . . . . . . . . . . . 182 Genus Araniella Chamberlin & Ivie . . . . . . . . . . . . . . . . . . . . 191 Genus Araneus Clerck . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 Genus Cercidia Thorell . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 Genus Eustala Simon . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 Genus Singa C.L. Koch . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 Genus Hypsosinga Ausserer . . . . . . . . . . . . . . . . . . . . . . . . 280

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Genus Zygiella F.O. Pickard-Cambridge. . . Genus Acanthepeira Marx in Howard . . . . Genus Larinia Simon . . . . . . . . . . . . . Genus Metepeira F.O. Pickard-Cambridge . Family Theridiosomatidae. . . . . . . . . . . . . Genus Theridiosoma O. Pickard-Cambridge Glossary . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . Index . . . . . . . . . . . . . . . . . . . . . . . .

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Acknowledgments The authors are grateful to Donald J. Buckle, who contributed many specimens and locality data to this work and also gave a critical evaluation of the manuscript, and to Nadine Dupérré, who made the 52 original drawings. Raymond Hutchinson kindly revised the keys. Brent Opell provided a valuable review.

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Introduction This manual treats the Canadian orb-weaving spiders and their webs. Previous parts in the series dealt with crab spiders (Dondale and Redner 1978), sac spiders (Dondale and Redner 1982), wolf, nurseryweb, and lynx spiders (Dondale and Redner 1989), and ground spiders (Platnick and Dondale 1992). This part is based on a series of generic revisions by Gertsch (1964), Muma and Gertsch (1964), Levi (1968-2002), Berman and Levi (1971), and Coddington (1986c). We also incorporated some locality data of verified specimens from the Canadian National Collection of Arachnids. Orb-weaving spiders build the two-dimensional wheel-shaped webs often seen in hedges, meadows, and weedy waysides. These webs have long inspired wonder as objects of beauty. They are most noticeable when covered by dew or fog, and it was such a sight that moved Fabre (1905), the poet-naturalist of Provence, France, to write: “Considérons, par une matinée brumeuse, le réseau qui vient d’être construit pendant la nuit. À cause de leur hygrométrie, les gluaux se sont chargés de gouttelettes et, fléchissant sous le poids, sont devenus autant de chaînettes, autant de chaplelets de gemmes limpides, gracieux chapelets rangés en ordre exquis et retombant en courbes d’escarpolette. Si le soleil perce le brouillard, l’ensemble s’illumine de feux diaprés et devient splendide girandole.” But the orb web, however attractive to the human eye, is really an aerial trap capable of arresting the flight of an airborne insect and entangling the prey on the sticky threads of the web. The owner of the web detects the struggles of the insect, and attacks. Witt (1968) was aware of this scenario when he compared the nocturnal construction of the web to the preparation of a gallows. Fabre (1905), too, recognized the true nature of the web: “Il faut manger pour avoir de la soie, il faut avoir de la soie pour manger, et surtout pour ourdir le dispendieux cocon de la famille.” Hence the web is a kind of investment in which protein is expended, and the “pay-off” is food which ideally will not merely replace the protein used in the web but will provide sufficient energy for the production of the spider’s offspring. There is solid evidence in orb weavers for a direct relationship between foraging success and reproductive success (Sherman 1994).

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Methods The collector can collect individuals of some orb weavers from herbs and shrubs (Argiope spp., Mangora spp., Neoscona spp.) with a sweeping net. He can dislodge those that inhabit tree foliage (Cyclosa spp., Araniella spp., Metellina spp., Araneus nordmanni, Uloborus glomosus, Hyptiotes spp.) on a sheet held beneath the branches as the latter are hit with a series of sharp blows from a stick. He can collect individuals that build on cliffs, among boulders, or on fences and buildings (Araneus diadematus, Larinioides spp., Zygiella spp., Aculepeira spp., Theridiosoma gemmosum) by holding a sheet or net beneath the web and inducing the spider to drop; the specimen can then be steered into a vial. Collecting difficulties with litter dwellers (Pachygnatha spp., Hypsosinga spp.) can be overcome with the use of pitfall traps set in the ground (Martin 1977). Rearing of orb weavers requires much time and patience. Witt and Reed (1968) attempted to provide natural conditions of light, temperature, and humidity in the laboratory using 16 hours of light daily and varying temperatures and humidities. Houseflies were used to feed the stock, and the cages were of glass and screen over aluminum frames. The three species reared by these authors were Araneus diadematus, Zygiella x-notata, and Larinioides sclopetarius. Management of web production, however, was not always successful, particularly in winter. Web photography is facilitated by the application of a fine mist to the threads with an atomizer. Alternatively, the photographer can take advantage of a dewy or foggy day. Or one can make the threads more visible by means of a dusting of corn starch, in conjunction with a piece of dark material placed behind the web. Eberhard (1976) gives further methods. Identification of orb weavers is not easy, and it requires close attention to anatomical detail. The largest representatives can sometimes be identified by their size and color, but all identifications should be confirmed by microscopic examination of the external genitalia (see below). Juveniles should not be named to species because of the existence of closely related species, distinguishing of which can only be made with confidence on adult material. Juveniles can, however, be sometimes reared to maturity (see above). Specimens destined for a collection can be killed in 75% alcohol. Storage is in the same liquid after one or two changes of alcohol. Leaving the specimens (and alcohol) in a refrigerator for a few days initially seems to prevent separation of the body wall from the internal organs (James Berry and Brent Opell, personal communication). The specimens are stored in vials, with collection data and name of the species, and then placed in preserving jars fitted with rubber rings. Specimens are examined under a binocular microscope having magnifications ranging from 10X to 50X. If one needs to see the spermathecae, he should first cut off the entire epigynum and immerse it for a few minutes in oil of cloves to clear the structures inside it. After

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it is examined, the epigynum is then stored in a microvial and this in turn in the larger vial used to hold the rest of the spider’s body. Examination of palpi is made easy if the examination dish contains a layer of fine sand, fine glass beads, or black silicon carbide as a cushion. The specimen must be completely immersed in the alcohol in order to prevent light reflections. In this manual, the sizes of specimens are indicated as follows: for samples of 1–3 specimens, the individual measurements are given; for 4–7 specimens, the mean and range are given; and for 8–10 specimens, the mean and standard deviation are given. The maps include localities from revisions relevant to the United States of America. Official common names of species are given where available.

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Anatomy The term anatomy is used here to denote the facts of structure. Sufficient detail is given to permit the positive identification of the families, genera, and the 94 known species of orb-weaving spiders believed to be represented in Canada. An orb weaver’s body, like that of any spider, comprises an undivided cephalothorax in front and an abdomen behind, the two divisions connected by a slender pedicel which permits flexibility between the two body regions (Fig. 2). The cephalothorax bears the four pairs of legs (numbered I to IV from the front), the mouth parts, and the eyes. The legs are composed of seven segments, namely, coxa, trochanter, femur, patella, tibia, tarsus, and pretarsus (Fig. 1). The tarsus is secondarily subdivided into basitarsus and distitarsus and the tiny pretarsus bears the claws. Two of the claws form a pair and are usually relatively large; they

Figs. 1, 2. Diagram of female orb weaver. 1, dorsal view. abd, abdomen; btar, basitarsus; car, carapace; cx, coxa; dtar, distitarsus; fe, femur; gr, dorsal groove; pat, patella; tib, tibia; tro, trochanter. 2, Diagram of female orb weaver, ventral view. abd, abdomen; at, anal tubercle; bl, book lung; blo, book-lung opening; ceph, cephalothorax; chel, chelicera; col, colulus; cx, coxa; epig, epigynum; gg, genital groove; lab, labium; ped, pedicel; st, sternum; trsp, tracheal spiracle.

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are sometimes toothed (Fig. 3). The third claw is usually smaller and untoothed; it gives the spider its grip on the web. Several kinds of specialized setae are found on the legs, some of which are useful in identification. These include the strong erectile macrosetae, the sensory trichobothria (which are exceedingly fine, erect, and seated in tiny circular pits (Fig. 3)), and other kinds according to group. There may also be true spines of various sizes. Cribellate orb weavers possess a dorsal comb of stiff curved setae on basitarsus IV; this is the calamistrum (Fig. 5) (see below). The orb weaver’s mouth parts comprise the palpi, rostrum, and chelicerae. The palpi (Fig. 10) are leglike and of six segments, namely, coxa, trochanter, femur, patella, tibia, and tarsus. The tarsus is undivided, and may bear a single claw, but in mature males the terminal segment(s) develop into the secondary mating organ unique to all spiders. The coxa of each palpus possesses a lobe called the palp-coxal lobe; the pair of lobes together cover the sides of the mouth. These lobes also assist in crushing prey and bear glands that release digestive secretions. The rostrum is a small unpaired sclerite ordinarily not seen because it is concealed by the carapace front; it closes the mouth in front. The chelicerae (Fig. 6) are typically large and strong, being used for seizing and crushing prey. The chelicerae are also used in combat, in the cutting of silk threads, and in other ways. The swollen basal segment has a furrow along its distomesal surface in which the fang lies when not in use. There are usually teeth along the prolateral and/or retrolateral margins of this furrow. A venom gland lies within the basal segment of the chelicera; it opens near the tip of the fang. The eyes of orb-weaving spiders (Fig. 7) are simple (as opposed to compound) each composed of a single lens and retina. They are usually eight in number. They are called anterior medians, anterior laterals, posterior medians, and posterior laterals. Size of the space between various pairs of eyes, and the curvature of the rows of eyes, are sometimes useful in identification. The dorsal plate covering the cephalothorax is the carapace, and the corresponding ventral plate is the sternum (Figs. 1, 2). The carapace is marked, near its middle, by the dorsal groove, which is a pit on whose inner surface certain dilator muscles of the sucking stomach originate. Anterior to the sternum is a small triangular sclerite, the labium, which covers the mouth posteriorly and lies between the palp-coxal lobes. The abdomen of orb weavers may be rounded, elongated, humped, or flat. It bears the spinnerets posteriorly, and, ventrally near the anterior end, a long transverse seam called the genital groove (Fig. 2). The spinnerets (Figs. 8, 9) are in three pairs called anteriors, medians, and posteriors. The arrangement of the tiny spigots on the spinnerets is of use in the classification of these spiders (Coddington 1990a, 1990b, Platnick et al. 1991). Posterior to the spinnerets is the anal tubercle, and anterior to them are the colulus (or its homolog, the cribellum) and 5

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Figs. 3–6. 3, Distitarsus of an orb weaver, retrolateral view. pcl, paired claws; trich, trichobothria; ucl, unpaired claw. 4, Underside of cephalothorax of male orb weaver showing common modifications to coxae I and II: cx I, coxa I; cx II, coxa II. 5, Tarsus IV of uloborid spider showing calamistrum, prolateral view. btar, basitarsus; dtar, distitarsus. 6, Chelicera of orb weaver, prolateral view.

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Figs. 7–10. 7, Anterior part of carapace of orb weaver showing eye arrangement. ale, anterior lateral eye; ame, anterior median eye; ple, posterior lateral eye; pme, posterior median eye. 8, Spinnerets of orb weaver, ventral view. ant. spin., anterior spinneret; col, colulus; med. spin., median spinneret; post. spin., posterior spinneret. 9, Spinnerets of uloborid, ventral view. crib, cribellum. 10, Palpus of female orb weaver, ventral view. cx, coxa; fe, femur; pat, patella; plpcx, palp-coxal lobe; tar, tarsus; tib, tibia; tro, trochanter.

the tracheal spiracle. At the midline in the genital groove is the genital opening in both sexes. Also, at the lateral extremities of the genital groove lie the openings of the book lungs. The external genitalia are much used in orb-weaver identification and classification. They are the epigynum (Figs. 11, 12), with its associated copulatory tubes and spermathecae in females and the palpal mating organ in males. The female genital opening is usually associated with a sclerotized plate, the epigynum, which carries the paired copulatory openings on its surface. These openings may be found in a depression called the atrium, in paired atria, or, at the sides of

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Figs. 11, 12. Epigynum of orb weaver. 11, ventral view. atr, atrium; ls, lateral sclerite; s, scape; spt, spermatheca. 12, lateral view. co, copulatory opening; ct, copulatory tube; spt, spermatheca.

a protruding spur known as the scape. The openings lead the emboli of the male organ into the copulatory tubes, which terminate in the semen-storing organs known as spermathecae. A few groups of orb weavers, such as Tetragnatha spp., lack a sclerotized epigynal plate, and the emboli of the male enter the copulatory tubes directly from the genital groove. The oviduct, through which the eggs pass from the ovaries to the outside, is connected to the spermathecae by a pair of short tubes, the fertilization tubes. Fertilization takes place as the eggs leave the female’s body. The mating organ of males (Figs. 13–16) involves mainly the terminal segment, though in some cases the tibia, patella, and even the femur and coxa may 8

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Figs. 13, 14. Palpus of male orb weaver. 13, dorsal view. cym, cymbium; fe, femur; pat, patella; tib, tibia. 14, partly expanded, prolateral view. con, conductor; cym, cymbium; e, embolus; ma, median apophysis; pc, paracybium; sd, sperm duct; subterm, subterminal apophysis; teg, tegulum; term, terminal apophysis.

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Figs. 15, 16. Palpus of male orb weaver. 15, fully expanded, prolateral view. basal hemat, basal haematodocha; con, conductor; cym, cymbium; e, embolus; ma, median apophysis; pc, paracymbium; sd, sperm duct; subteg, subtegulum; subterm, subterminal apophysis; teg, tegulum; term, terminal apophysis. 16, partly expanded, ventral view. con, conductor; cym, cymbium; e, embolus; el, embolar lamella; ma, median apophysis; pc, paracymbium; sd, sperm duct; subteg, subtegulum; subterm, subterminal apophysis; teg, tegulum; term, terminal apophysis.

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be involved. The complex bulging structure on the ventral or mesal side of the tarsus is the genital bulb, which lies cupped within a concavity of the cymbium. The cymbium can be recognized by its covering of setae and by its flexible attachment to the tip of the tibia. The largest sclerite of the bulb is usually the tegulum. Distally the tegulum gives rise to the embolus, which is the intromittent organ used in introducing semen into the spermathecae during copulation; the embolus can be identified by the seminal duct entering its base from the semenstoring reservoir. Other sclerites arising from the distal part of the tegulum include, in various groups, a conductor, which functions as a support for the resting embolus, a median apophysis, and a terminal apophysis. The embolus, conductor, and terminal apophysis are often together set off from the tegulum by the distal haematodocha. The median apophysis is also flexibly attached, and the terminal apophysis itself may be similarly attached on the rest of the complex. Males of the Araneidae have a small sclerite interposed at the base of the embolus and through which the seminal duct passes; this is the radix (Coddington 1990a). Males of the Tetragnathidae lack a median apophysis, and the embolus and conductor are usually long and spiralled. The palpal patella of orb weavers is often modified by the development of one to three long dorsal macrosetae. The tibia may also have such setae. Tibia I and/or II in some groups may bear thickets of stout peglike macrosetae, and the coxa of leg I may have a ventral hook which is thought to lock leg I to leg II during mating (Fig. 4).

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Definition of orb-weaving spiders The orb weavers represent two basic lineages.The first of these lineages is a large group comprising such families as Araneidae, Tetragnathidae, and Theridiosomatidae, which produce the catching spiral of the orb from silk made by two kinds of abdominal glands, namely, a pair of flagelliform glands and two pairs of aggregate glands (see below). The flagelliforms produce the non-sticky core of the thread, and the aggregates the sticky coating (Kovoor 1987, Peters 1987, Vollrath and Tillinghast 1991). The gluelike coating tends to separate into droplets along the thread, forming various patterns (Peters 1987). Silk from both kinds of gland is emitted from the posterior spinnerets. Production of silk by spiders of this lineage is regarded as much more economical than production by those of the following lineage (Opell 1997, 1998). The other lineage of orb weavers comprises the so-called cribellates, represented by the families Uloboridae and Deinopidae. These spiders possess a conspicuous flat spinning plate, the cribellum, anterior to the spinnerets on the underside of the abdomen (Fig. 9). The plate is covered with great numbers of fine spinning tubes that emit sticky silk. The cribellate orb weavers also possess, on the dorsal surface of each hind basitarsus, a comb of rigid setae collectively called a calamistrum (Fig. 5). When spinning its web, the spider holds one hind leg beneath the abdomen in such a way that the calamistrum draws silk from the cribellum; this is accomplished by a rhythmic swinging of the leg forward and backward. The spider may alternate, at intervals, use of right and left hind legs. The cribellar silk is combined with a non-sticky core produced by the pseudoflagelliform glands. The latter silk is emitted from the posterior spinnerets (Peters 1987). The production of orb webs in two different ways as described above has given rise to a long-standing controversy among arachnologists, i.e., “the single versus the dual origin of the orb web” (Coddington 1986a). Coddington (1986a, 1986b, 1990a, 1990b, 1990c) chose the former theory as best explaining the available evidence, and elaborated a substantial list of unique characters held in common by both cribellate and ecribellate orb weavers, among which are a number of modifications in the silk glands or in the kinds and numbers of silkemitting spigots, in special setae on the body or legs, in specializations in the external genitalia, and a possible nine behavioral characters manifested in web construction or in the so-called wrap attack on ensnared prey. A correlate to Coddington’s inferences is that whereas the cribellum and calamistrum have both been retained in the Uloboridae and Deinopidae, they have been lost in the ecribellate orb weavers, a phenomenon that is thought to have occurred in many other groups of spiders, even, in some instances, among the species of a single genus (Platnick 1977). Coddington (1986a) maintains that the cribellate orb weavers are more closely related to the ecribellate orb weavers than to any group

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of cribellate spiders, and that the ecribellate representatives are more closely related to the cribellate orb weavers than to any group of ecribellates. Coddington (1990a, 1990b) and others later discovered orb-weaver specializations in other groups of ecribellates. These include a vast assemblage of spiders comprising the families Theridiidae, Nesticidae, and Linyphiidae, whose webs have lost all demonstrable resemblance, except for the inclusion of sticky silk, to orbs. Recent corroborative evidence for the relationship of araneids and linyphiids was found in the spinning apparatus of Linyphia triangularis by Peters and Kovoor (1991). The entire group includes the following, as currently listed: Superfamily Deinopoidea Family Deinopidae Family Uloboridae Superfamily Araneoidea Family Araneidae Family Tetragnathidae Family Theridiosomatidae Family Mysmenidae Family Anapidae Family Symphytognathidae Family Linyphiidae Family Nesticidae Family Theridiidae Family Cyatholipidae Family Pimoidae Family Synotaxidae These families comprise the group Orbiculariae, which, in view of the unique characters held in common by these spiders, is regarded as a monophyletic group. The group includes more than 10 000 species, or upwards of a third of all the world’s described species, with an estimated 850 in Canada alone. Such a large number can hardly be treated in a single manual, not only for reasons of size but because most of the genera and species need proper identification. We therefore restrict the current work to the families Uloboridae, Araneidae, Tetragnathidae, and Theridiosomatidae, all of which have been revised for North America in recent years.

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Nature of orb webs Observers as early as the 4th century B.C. have recorded their fascination with orb webs. Aristotle described the various parts of the web, the hunting posture at the hub, the fierce wrap attack by which the spider subdues large prey, and the method of feeding (Thompson 1952). Many scattered observations were drawn together and augmented with original notes by Emerton (1878). Fabre (1905) meticulously recorded the steps by which the orb is made in a half dozen species that he found on the rosemary hedges surrounding his garden in Sérignan, France; the geometry of the orb particularly drew his attention, but the bridge and frame placement largely escaped his eye. The latter operation, by which the spider appears to be “staking out space” (Reed 1968) for the aerial trap, only gradually began to be understood with the work of Wiehle (1927), Peters (1937, 1939a, 1939b), Savory (1952), and Witt et al. (1968). Even today there is no coherent and complete account of the choice of web site nor of the perception of a web space by any orb weaver. Much remains to be learned.

Ecribellate webs If we observe the construction of the web of a common orb-weaving spider such as the Cross Orbweaver (Araneus diadematus Clerck), a favorite experimental animal, we see a process divided roughly into four phases. In phase one, the spider establishes the framework that will form the boundary of the space in which the aerial trap will be spun. Phase two is the laying of the radial threads from a central point to the boundary. Phase three is the spinning of the temporary, or auxiliary, spiral, and phase four is the replacement of the auxiliary spiral by the sticky spiral, which is the primary prey-catching part of the web. The phases are not entirely clear-cut, but may merge when, for example, the spider leaves off radial-thread construction and temporarily reverts to peripheral frame construction. Phase one begins with the emission of a thread into the air (Eberhard 1987a) from some prominence such as a post or plant stem. This thread requires moving air in order to function, and it usually catches on some object down wind. The spider detects this catching in some manner and hauls up the slack in the thread, then fastens the thread to the substrate where the spider stands. The spider then cuts the thread with its chelicerae, grasps the free end in its front legs, and pulls itself along the latter while rolling the silk in front into a ball and spinning a new thread behind. This new thread is the bridge (Fig. 17a). An alternative method of making the bridge is described by Savory (1952:73); this method is used when the breeze is coming from below rather than the side. The bridge thread, once in place, is often strengthened by the addition of extra threads along it. The bridge, as Savory (1952) observed, is “a structure on which the whole of the rest of the web depends.”

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Fig. 17. Production of an orb web. a, establishment of the bridge thread AB; b, doubling of bridge thread and spinning of thread AXB; c, pulling down the thread AXB to position AX'B and establishing contact with the substrate at Y; d, doubling the thread X'C; e, extending the secondary thread X'C toward the hub and across the angle formed by threads AX' and BX' to a point E on thread AX'; f, thread fastened loosely at D is then pulled taut, thus forming the frame thread ED'C; g, additional radial threads and frame threads added as in e, f; h, i, addition of other radial threads; j, k method of applying the auxiliary spiral thread; l, m, method of applying the auxiliary spiral thread in the outer parts of the web.

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Bridge construction is followed by the establishment of a Y-shaped figure below the bridge (Figs. 17b, 17c). Difficult to observe, this operation has eluded many a patient observer and is still clouded with uncertainty owing to inconsistency in its creation. The most common method appears to be the spinning of a second bridge thread parallel to the first (AB) and the drawing downward of this secondary thread, first from point X to X' and then, as a single line, to the substrate below (Y). The point X' represents the future centre of the web, and the three lines AX', BX', and X'Y are the first, or primary, radii of the web. Three secondary radii are next established, and this proceeds in conjunction with completion of the peripheral frame threads. The spider attaches a thread at the centre (X'), carries it loosely on one hind tarsus to point C, where the thread is fastened, thus doubling the line X'C (Fig. 17d). The spider then works toward the centre to a point D, where it fastens a line to the new X'C, and carries this

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loosely to the centre and then along X'A to a point E (Fig. 17e). Here the spider draws the thread DE toward it so that the secondary line X'DC becomes X'D'C, a secondary radius, and the thread ED'C becomes a peripheral frame thread (Fig. 17f). The spider then replaces the line X'D' with a new one. This operation is usually done in the upper half of the web. Returning to the centre once more, the spider now repeats the placement of a secondary radius in each of the two remaining segments in the lower half. The central or catching area of the web is now defined at the edges and partly framed internally. Additional frame threads are typically added at this stage, as in Fig. 17f (AY, BY). The remaining radii are next put in place. Beginning at the centre, X', the spider tugs rapidly at the bases of the established radii, one at a time, thus appearing to test either the width of the angle between the radii or the relative tension on the various radii, or both, rotating its body rapidly at the centre. The spider’s rotation may be either clockwise or the reverse, but is usually clockwise in the right half of the web and counterclockwise in the left half (Reed 1970). The spider, having obtained in some manner the information needed to carry on, next runs along one of the established radii to a peripheral frame thread, AY or BY, carrying a thread loosely on one hind tarsus (Fig. 17g). It moves along the peripheral thread to a particular point, stops, draws the loose line taut, and fastens the latter to a peripheral thread. The spider returns to the centre and repeats the process until all radii are in place (Fig. 17h). Each of these radii is laid approximately opposite the one just made, and the resulting angle between the 20–35 radii at completion of this phase is, for A. diadematus, approximately 15°. The pull of gravity apparently results in more radii in the lower half of the web than in the upper. Activity at the centre has, by this time, produced a sort of mat, or hub, formed of the bases of the radii and some interconnecting threads. The third phase of orb construction is the production of the auxiliary spiral. Here the spider begins by laying down a thread from a position somewhat removed from the outermost turns of the hub to the outer region of the incomplete web, moving clockwise or counterclockwise across the radii in an ever widening circle (Fig. 17i). Only one third or less of the web surface may be covered by the auxiliary spiral, and there is also a free zone devoid of spiral threads between hub and the innermost turn of the spiral (Fig. 17j). At each junction the spiral thread is cemented to the radial, a move that imparts strength to the web. The auxiliary spiral is thought by some workers to be a sort of guide for the placement of the sticky spiral (see, for example, Eberhard 1972:453 and Zschokke 1993). Some orb weavers, however, omit the auxiliary spiral and yet make the sticky spiral successfully. Production of the sticky spiral, which is the fourth and final phase of orb building, may occupy up to 80 per cent of the 25 minutes or longer spent in the building of the web (Reed 1968). Standing at the web’s periphery, the spider first remains motionless for a time. This “rest” lasts from a few seconds to several

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Fig. 18. Diagram showing one-half of a completed orb web.

minutes and marks the boundary between the third and fourth phases of web construction. Savory (1952) points out that whereas, up to this point, the spider has been spinning non-sticky silk at a rapid and continuous pace, it now begins to spin sticky threads that are put into place much more slowly and deliberately. Moreover, the sticky spiral is laid from the periphery of the web to the centre and proceeds in the reverse direction to that used in the spinning of the provisional spiral. Reed (1968) suggests that the pause is required by the shift in glandular source, for silk from the aggregate glands is now brought into use for the first time, becoming the sticky coating of the sticky spiral. The actual function of the pause remains unknown.

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The spider begins the sticky spiral by attaching a line to one of the radii. It then moves along that radius, carrying a thread loosely on one hind tarsus, toward the web’s centre until it finds with a front leg the outermost turn of the provisional spiral, thence along the latter to the next radial, and along that radial toward the periphery where, at a particular point determined by a lateral tap of leg I, or of legs I and II, the line is drawn taut and fastened (Figs. 17k, 17l). The spider then moves toward the centre once more and attaches the sticky line in the next sector. This operation is repeated until the spiral is complete. The space between adjacent turns is kept uniform by the regular measuring of the spider’s lateral tap at each intersection of the sticky thread and a radial thread. Nearer the centre the radials are closer together, and the spider does not need to take the circuitous route that it did in the outer reaches of the web but can simply step directly across the gaps between radii. The sticky spiral usually stops short of the centre, just as the provisional spiral begins beyond the centre, and this leaves a space between the hub and the catching area of the web. This space is known as the free zone. Another feature commonly seen in webs of A. diadematus is a disproportionate number of partial turns in the lower half. This is brought about by a frequent reversal in direction in this part of the web. A diagram of the left half of a completed orb web is shown in Figure 18. Production of the sticky spiral is accompanied by removal of the auxiliary spiral. The spider may make several turns of the sticky spiral in the outer part of the web before it meets the outermost thread of the auxiliary spiral. Thereafter the spider gathers the auxiliary thread into its mouth as it spins the sticky thread behind it. The nature of the junctions between the sticky spiral and the radii are still poorly understood, though chemical analyses suggest that the junctions have an origin different from those of the auxiliary-spiral thread with the radii (reviewed by Tillinghast and Townley, 1987:207). The final act of orb-web construction by A. diadematus is the partial removal and consumption of “the flocculent tangle left by operations at the hub” (Reed 1968). These remnants result from the spider’s movements as it joins the radii at the centre. The rather thick mat remaining at the centre now serves as a platform upon which the spider takes its stand, ready for the hunt. With legs spread outward upon the bases of the radii, it can detect and respond instantly to the vibrations set up when an insect strikes the web. Webs often become torn in use, and repairs may be made soon after the prey is subdued and before feeding begins. Sometimes the spider goes on catching prey on its tattered web, without making repairs. Much of the catching part of the web is reconstructed nightly in any case, thread by thread, with the torn lines being eaten and digested, then later reconstituted as new silk (Savory 1952, Peakall 1971).

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Orb webs are usually planar structures, i.e., they exist in only two dimensions, in contrast, for example, to the three-dimensional webs of the comb-footed spiders. The orb is, however, subject to several kinds of modification. Young spiders may make webs that are more regular than those of adults of the same species (Witt and Reed 1968). The same authors showed that changes in web pattern can be experimentally induced by excision of a pair of the spider’s legs, the addition of weights to the spider’s body, the withholding of food, or the administration of a variety of pharmacological agents. Eberhard (1988) demonstrated alterations to web parameters in relation to depletion of silk supplies in various silk glands. Gravity, which has been thought by some authors (Peters 1937, Vollrath 1986) to play an important role in the shape and pattern of the web, is apparently not essential to successful construction, as shown by the specimens sent into earth orbit by Witt et al. (1977). Interspecific variation can occur in the number of radii and of spirals, in the production or non-production of a stabilimentum, in various degrees of reduction of the orb, and in the construction of silken structures outside the orb proper. The stabilimentum merits special consideration. As its name suggests, this structure was originally interpreted as strictly a strengthening device, consisting of a band of dense white silk placed zigzag fashion between two radii, or of a slender band of silk like a partial spiral. One outstanding departure from these general types is the straight vertical row of debris made through the centre of the web of Cyclosa conica (Pallas); the spider’s egg sacs are placed in the row, and even the spider’s body, huddled at the centre, becomes part of the same row. This suggests a camouflage function. Other functions may include protection from predation, attraction of prey, and protection from excess solar radiation (Robinson and Robinson 1973, Horton 1980, Eisner and Nowicki 1983, Edmunds 1986, Neet 1990, Cloudsley-Thompson 1995, Tso 1996, 1998). Robinson and Robinson (1973), Nentwig and Heimer (1987), Eberhard (1990), and Blackledge (1998) discuss current theories regarding the functions of various kinds of stabilimentum. Scharff and Coddington (1997) thought the stabilimentum “uninformative phylogenetically.” A quite different kind of modification to the orb is that made by Theridiosoma gemmosum. This spider spins a so-called tension line (Coddington 1986c), or trap line (Gertsch 1979), between the hub and some nearby object such as a plant stem. It then stations itself upright at the point where the web radii converge, gripping the web with its legs III and IV, and draws the web into a conical shape by means of its powerful legs I and II. When an insect strikes the cone, the spider releases the tension on the line, thus entangling the prey in a way reminiscent of the hunting tactic of the Triangle Weaver Hyptiotes cavatus (Hentz) (Family Uloboridae). The tension line has been proposed as a modified signal thread (Wiehle 1931).

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Cribellate webs Cribellate orbs are similar to ecribellate webs, both in the method of construction and in the final product. The main differences are the source of the sticky silk and a strong tendency toward horizontality. The horizontal web catches mainly insects that fly upward (for example, from the surface of water). The web of the Featherlegged Orbweaver, Uloborus glomosus (Walckenaer), only 10–15 cm in diameter and usually placed among low shrubs, in tree cavities, or among stones, is typical. Web building begins with exploration of the site and proceeds through establishment of a bridge thread, construction of radii and auxiliary spiral, and finally the replacing of the auxiliary spiral by the sticky spiral (Gertsch 1979:140). The radii are laid in the same way as by the Cross Orbweaver, with apparent testing of the tension after each radius is completed. The sticky spiral is a composite of dry silk from the posterior spinnerets and sticky silk from the cribellum (Peters 1987). The hub of the web of U. glomosus is closely meshed and continuous with the auxiliary spiral, and there is usually a stabilimentum. The stabilimentum is often a band of strong silk crossing the web through the hub, but it may also be Vshaped, cross-shaped, or circular (Gertsch 1979). The spider’s hunting position is at the hub, on the lower side of the web. Egg sacs are placed in a row across the web, and they, as well as the spider, resemble bits of debris. The western species U. diversus Marx, not treated here, has been studied in more detail (Eberhard 1969, 1972, 1977). There is variation in the webs made by different species of cribellate orb weavers, just as there is among the webs of the ecribellates. The Triangle Weaver builds a reduced orb, that is to say, a web reduced to three sectors (Wilder 1875, Emerton 1878, Gertsch 1979, Opell 1982b). This spider lives among dead branches and twigs, often on pine trees, but sometimes in deciduous trees or in underbrush. The web is vertical and triangular, spanning an arc of some 50°–60° and having four radii of approximately 30–50 cm length. The radii diverge from a bridge thread attached to a nearby twig. The spider establishes the bridge thread either by letting the line drift on an air current or by carrying the line loosely on one tarsus to some nearby mooring. A vertical thread is then attached near one end of the bridge and fastened to a twig lower down. Another thread joins the lower end of this vertical thread to the bridge, thus completing the triangle. Two additional radii are then placed within the triangle, extending from the hub to points along the vertical thread. The spider next spins three or four non-sticky spiral threads, beginning at the hub and extending about half the distance toward the vertical thread. The sticky spiral is laid upon the uppermost sector first, then upon the middle sector, and finally upon the lowermost sector. The spider begins this operation by fastening a thread near the outer extremity of the uppermost radius, then

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carrying it loosely on a hind tarsus toward the hub untill the outermost thread of the auxiliary spiral is met. The spider moves downward along this thread, removing the auxiliary thread as it goes, to the second radius, and thence outward along this radius to a point beneath the starting point. There the sticky thread is drawn taut and fastened to the second radius. The spider then returns to the uppermost radius and repeats the process from a point somewhat closer to the hub; this continues until all 10–20 or more of the sticky spiral turns are in place within the uppermost sector. The spider then moves to the middle and lower sectors in turn until all is complete. The sticky spiral, probably because it is laid one sector at a time, tends to be somewhat zigzag. The Triangle Weaver takes the hunting posture by suspending itself, front downward, on the short length of bridge thread adjacent to the hub of the web. Turning toward the net, it draws a loop of the bridge thread toward itself using its front legs and stands motionless. When an insect flies into the web, the spider “lets go with her hind legs, and the net springs forward, bringing more threads into contact with the insect, and sliding the spider along the line...” (Emerton 1878). The spider then approaches the prey, gathering up silk as it moves and covering the insect with this as a further entanglement. The prey is then carried to the hub where feeding takes place. The Triangle Weaver does not bite its prey in connection with wrapping because, like all uloborids, it lacks venom glands. Instead, it depends on entanglement and wrapping alone (Opell 1988b). Web building and prey capture by several tropical members of the Uloboridae are described by Gertsch (1979), Lubin et al. (1982), Lubin (1986) and Eberhard (1987b, 1988).

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Production and uses of silk Silk production from abdominal glands is unique to spiders and is an essential element of their lives. Unlike the silk of insects, spider silk is produced from early life, when the mouth parts and spinnerets first form, until death. The silk also appears in a variety of physico-chemical forms from the body of a single individual. The different silks are related to use, which may include web silks, drag lines, egg sacs, stabilimentums, retreats, swathing bands, and ballooning threads (see Gertsch (1979) and Foelix (1996) for a classification of silk usage by spiders generally). Allusion has already been made to different kinds of silk used in production of the catching web. All of these silks are fibroids, or fibrous proteins. Adult females of the Cross Orbweaver were once said to possess “at least five sets” of silk glands (Peakall 1968). This has now been updated to seven sets. The glands are described in detail by Peakall (1968) and classified by Kovoor (1987). Using the technique of sacrificing and serially sectioning individual spiders after they have just completed various operations, Peakall (1968) was able to deduce the function of the silk from most of the glands. Silk glands in the Uloboridae include all of those found in the Araneoidea but differ in having two pairs of pseudoflagelliform glands, which open on the posterior lateral spinnerets, in place of the flagelliforms. Kovoor (1987) and Coddington (1986a) regard these special uloborid glands as probable homologs of the ecribellate flagelliforms. Like the latter, they produce the core fibre of the sticky spiral. Uloborids, in addition, possess a cribellum with numerous tiny spigots distributed over its surface, as already mentioned; these spigots emit the sticky material that coats the capture threads. Peters (1987) illustrates the fine structure of these threads, which often show a series of “puffs” or “cloudy distensions”; the latter are thought by many authors to result from the combing action of the calamistrum but may instead result from “rhythmic clamping movements of the posterior spinnerets” (Peters 1984, Eberhard and Pereira 1993). Opell (1993, 1995) investigated the mechanism for stickiness in the silk of Hyptiotes cavatus and several other cribellate spiders. Kovoor (1987) describes the histology and histochemistry of silk glands in many arachnids including orb-weaving spiders. Coddington (1989) illustrates the various kinds of spigots found on the spinnerets and, as far as possible, correlates these structures with Kovoor’s (1987) data on gland histology. Orb-weaver silk is an unusual protein. Short-chain amino acids such as glycine and alanine predominate both in total web silk and frame threads, egg-sac threads, swathing bands, and attachment discs (Peakall 1968). The same author also showed that egg sacs and swathing bands are both high in serine and low in glycine, compared with web silks. Further work on amino-acid composition of the contents of the ampullate glands is reported by Work and Young (1987) and 25

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by Lombardi and Kaplan (1990). Work on the molecular composition and physical properties of orb-weaver silks is reported by Work (1976, 1985), Vollrath et al. (1990), Xu and Lewis (1990), Dong et al. (1991), Townley et al. (1991a, 1991b), Vollrath and Tillinghast (1991), Bonthrone et al. (1992), Hinman and Lewis (1992), Stubbs et al. (1992), Beckwitt and Arcidiacono (1994), Lewis (1994), Stauffer et al. (1994), and Kaplan et al. (1997), among others. Silk is produced in the glands as a water-soluble liquid having a relative molecular mass in the order of 30 000 (Nephila sp.), according to Braunitzer and Wolff (1955). Its flow to the outside is controlled by the joint action of intraabdominal pressure and the diameter of the control valves at the tips of the spigots. Both factors are under control of the spider. On emission from the spigot the silk becomes a water-insoluble solid having a molecular weight some 10 times greater than that inside the gland. The transformation is believed to be brought about by re-alignment of the molecules due to stretching. The drag line of the Cross Orbweaver has a tenacity (g/denier) of 7.8 and denier (weight in g of 450m) of 0.07; such threads can be stretched by 31% or more (DeWilde 1943; F. Lucas, cited by Peakall 1968). Silk protein is largely conserved by consumption of it by the spider, which uses it in the renewal of the web (Peakall 1971, Townley and Tillinghast 1988). Such feeding appears to confer other benefits as well (Smith and Mommsen 1984). Thread thickness varies from much less than 1 µm to a few microns. The capability of silk to transmit vibrations in the web of the Bridge Orbweaver, Larinioides sclopetarius (Clerck), and other orb weavers is reviewed by Barth (1982, 2002), by Masters and Markl (1981), and by Masters et al. (1986). Craig et al. (1994) discuss the spectral properties of various silks. Ultrastructure of the sticky threads is becoming clear through the work of Peters (1995) and others. Some of the work on molecular structure of silk has the practical goal of transferring the silk-producing genes from spiders to bacteria or to milk-producing domestic animals, where these genes may lead to large-scale production of silk. The combined high tensile strength and high elasticity of drag-line silk invites such uses as bulletproof clothing, automobile bumpers, artificial ligaments and sutures, and arresting cables for aircraft making deck landings at sea (Work 1976, Beard 1992, Eliot 1993, Mello et al. 1994, Arthur 1994).

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Venoms Most spiders possess a pair of venom glands situated within the large basal segment of each chelicera and often extending into the cephalothorax. The Uloboridae, which possess no such glands, are the exception to this generality. The venom glands, when present, pass their contents to the outside via a pair of ducts that open near the tip of the cheliceral fangs. The main function of venom is the subduing of prey, but many spiders will defend themselves by biting and injection of venom if under attack or roughly handled. According to Foelix (1996, citing G. Schmidt 1973), no more than about 30 species of spiders are regarded as dangerous to humans. There are no orb weavers on Schmidt’s list, and only a few scattered references to bites by araneids or tetragnathids exist (Bonnet 1945, Gertsch 1955, Gorham 1968). Quistad et al. (1992) found orb-weaver venoms relatively weak in comparison with various medically important venoms produced by black widows and ground spiders. Gertsch (1979:233) lists among the “lesser offenders” representatives of three araneid genera, namely Neoscona, Argiope, and Araneus, all rather large when mature and capable of pricking a finger when picked off the web. The symptoms are “slight to acute initial pain, some redness and local swelling, and transitory illness usually without necrosis or systemic reactions.” Symptoms do not persist more than a few days. The discovery of potent chemical antagonists of the neurotransmitter glutamate in orb-weaver venoms has prompted several lines of pharmacological research (Early and Michaelis 1987, Budd et al. 1988, Michaelis et al. 1988, Blagbrough et al.1989, Usherwood and Blagbrough 1991, Magazanik et al. 1991, Mueller 1994). Another possibility lies in the use of araneid venom components as sources of novel kinds of insecticides (Quicke 1988).

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Habitats and diets Studies on spider habitats in general indicate that a close relationship exists between web site and diet (Janetos 1986, Gillespie 1987, Neet 1986, Nentwig 1987), though physical factors undoubtedly also play a part in web-site selection (Riechert and Gillespie 1986, Colebourn 1974, Hodge 1987a, 1987b). Individuals of the Araneidae that build in mines, cellars, wells, stone piles, and similar places are probably quite restricted in diet, whereas spiders occupying grassy fields catch a broad spectrum of Orthoptera, Homoptera, Diptera, Coleoptera, and Hymenoptera [summarized by Nentwig (1987)]. Habitat may also sometimes involve a preponderance of prey belonging to a particular group that happens to be in local abundance, e.g., Odonata in webs of Argiope aurantia Lucas (Howell and Ellender 1984). There are of course limits to size of prey that the spider can overpower, though these limits are quite broad, being nearly two orders of magnitude. The spiders’ use of sticky silk and of various attack behaviors give a strong advantage (Nentwig and Wissel 1986). On the other hand, some prey are able to avoid webs or even escape from the sticky threads by using a variety of behaviors (Nentwig 1987, Eberhard 1986, 1989). Such escapes tend to be concentrated in the upper half of the orb, where mesh size increases from hub to periphery (Rhisiart and Vollrath 1994). There is evidence that some orb webs visually attract certain kinds of flying prey (Horton 1979, Craig 1990, Craig and Bernard 1990, Craig and Freeman 1991). There is also a possibility, based strictly on laboratory experiments, that flies released in a cage containing a living orbweaving spider can induce earlier web construction by the spider. Such early webs tend to be smaller than normal ones and to be spun more rapidly than those by spiders caged without flies (Pasquet et al. 1994). The possibility that insect flight behavior may have influenced web design in some instances is discussed by Craig (1986) and by Craig and Freeman (1991). How do spiders choose web sites? They apparently use physical cues such as the availability of suitable supports, direction and velocity of the wind, temperature and humidity of the air, amount of light, and probably others when beginning to build. There is probably some degree of trial and error as well, as evidenced by the high rate of web abandonment often seen in experimental populations. Hodge (1987a, 1987b), for example, collected individuals of Micrathena gracilis (Walckenaer) in a deciduous forest and later released them in a nearby pine forest. The spiders then built webs, but soon moved and build in a new site. This movement continued until all of the recoverable survivors were again domiciled in the deciduous forest. Spiders that had been collected in the same deciduous forest, but then released there, remained in that habitat. The precise factors involved were not identified, but web destruction by unfavorable weather, as well as low food availability, were thought to be important limiting factors for M. gracilis in the pine forest. Food availability was also indicated as important in the relationship between a population of the Banded Argiope, Argiope trifasciata, and of its chief

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prey (Olive 1982). Janetos (1982a) reported that araneids, tetragnathids, and uloborids abandoned their web sites with a mean frequency of three days. He (Janetos 1982b) later indicated that food availability was a probable factor in the observed mobility, pointing out that the spiders tended to remain at the same site when prey was abundant at that site. Janetos (1986) reviewed the available information and pointed out a number of aspects of the problem needing research.

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Reproduction Gertsch (1979) defines courtship in spiders as “the series of actions that mark the period during which [the male] is endeavoring to gain [the female’s] recognition”, and mating as the orientation of their bodies “in such a way that the palpal organ can come in contact with the apparatus of the epigynum.” Before either courtship or mating can take place, however, the male must have reached sexual maturity, i.e., have developed functional genitalia and have transferred semen from the testes in the abdomen to the palpal organ. The transfer, known as sperm induction, occurs in two stages. The male first spins a tiny semen web on the substrate and ejaculates upon it. The second step is the absorption of semen into each palpal reservoir via the embolus and seminal duct. This done, the spider is ready to mate, and it begins to wander over the substrate while palpating the surface. Wandering ceases when the male contacts an attractive sex scent, or pheromone, which has been deposited by a mature female of the same species. Movement is then determined by the scent trail or by vibrations in the web. The organ that produces the female scent is unknown, as is the chemical nature of the substance itself. Work by Anderson and Tillinghast (1980) on the Yellow Garden Argiope, Argiope aurantia, and A. trifasciata, however, showed that GABA and derivatives of taurine, which appear in different proportions in the webs of adult females of the two species, may convey chemical information permitting recognition by the respective males. The male’s chemosensory setae are situated on the tips of the palpi and legs (Foelix 1996). Courtship in orb weavers tends to be a prolonged timorous affair and mating a brief resolute one. Blanke (1986) gives details for the Cross Orbweaver spider. The male, having charged his palpi with semen and found the female’s web, begins by tweaking the peripheral threads and vibrating his abdomen vigorously. In this way he signals his presence from a distance while his escape route remains open. If the female is receptive, she signals her response by plucking the threads in turn. The male then spins a special thread called the mating thread, fastening one end to the female’s web and the other to a nearby support such as a plant stem. This thread may be reinforced with several additional threads, which are laid upon the first. The female now moves to the mating thread, where she hangs motionless, venter and legs upward, by her spinnerets and legs IV. Legs III are brought together at their tips, forming a characteristic “ring”. Her legs I and II are drawn backward at an angle to the body. The male approaches the motionless female and begins to tap her front legs with his legs I. Simultaneously his legs II tap her mouth parts and sternum. Abruptly the tapping ceases, and courtship gives way to copulation. The male quickly applies one of his palpi to the epigynum, at the same time drawing close to her body so that the abdomens of male and female lie parallel. The swelling of

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the haematodocha is generally regarded as a sign that the embolus has been inserted and that semen is being transferred to the spermathecae. The haematodocha swells and subsides many times (7–28 times, according to Blanke’s observations), and the male then withdraws the embolus and applies the alternate one to the alternate epigynal opening. Blanke observed 3–10 swellings of the haematodocha for the second side, after which the male abruptly withdrew and left the web. On some occasions, however, the male was not quick enough and was wrapped and eaten by his mate. Courtship and mating in the Marbled Orbweaver, Araneus marmoreus Clerck, also observed by Blanke (1986), differs little from the process in the Cross Orbweaver spider. Courtship in Zygiella x-notata Clerck differs from the foregoing in a number of details (Blanke 1986). The male first signals his presence by plucking and tapping the female’s signal thread, then ascends and fastens one end of his mating thread directly in front of the ensconced female. The latter then emerges and takes a position on the mating thread, hanging from it venter uppermost. The female’s legs III make a “ring”. The male begins tapping the female’s sternum and leg tips. After a period of this, he pushes his legs I against the female’s sternum and raises his body so that his palpi are brought close to the epigynum. One or the other embolus is inserted, and the haematodocha swells. The female often bestirs herself at this point and returns to the retreat. The male then renews tapping. Alternately the female may permit one or more further insertions without leaving the mating thread. Many insertions are the rule, though a maximum of five on a side in a single series was recorded by Blanke. The male disengages suddenly and leaves the web. A male of the genus Pachygnatha, a group in which the adults make no webs (though the young may do so, as shown by Martin (1978)). According to Gertsch (1979), the male “prowls among the grass roots and finds his mate by touch. He seizes her and, aided by special spines and long teeth on his chelicerae, holds her firmly until her mating instincts have become aroused or her hostility forces his retreat”. Males of Tetragnatha spp. also use a cheliceral locking hold on the females. This hold persists during copulation. Robinson (1982) gave further details of courtship and mating in orb weavers and in spiders generally. The female orb weaver stores the semen she receives in her spermathecae untill the oocytes from the ovaries pass from her body, when semen is released and fertilization takes place. Eggs are deposited in a special sac made from silk produced by the cylindrical glands. Sac construction in Argiope aurantia is described by Gertsch (1979). The spider hangs downward from its slightly inclined web and spins a series of cross threads as a sort of scaffold. Three layers of silk are applied in succession to the underside of this scaffold, the first an outer shell of firm yellowish silk, the

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second a thick intermediate bed of fluffy yellowish silk, and the third a firm inner layer of dark brown silk. The female then applies her abdominal venter to the brown layer and forces the eggs, mixed with a sticky amber fluid, against it. The round ball of yellow eggs is then covered with the same three layers of silk, but in reverse. Each layer is joined at the edge to its counterpart in the first half. The outermost layer later hardens and darkens giving the sac its characteristic shape, color, and crinkly texture. The sac is suspended by the female with threads among low shrubs or in leaf litter near the web site. The female of A. aurantia dies with the onset of winter, at least in the northern parts of its range, and the eggs hatch the following spring. The spiderlings bite their way out of the sac and disperse by ballooning, by which they ascend a post or plant stem and float away on the breeze, using the buoyancy of a thread drifting ahead of them.

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Family Uloboridae Members of the family Uloboridae are cribellate orb-weaving spiders allied to the Araneidae, Tetragnathidae, and Theridiosomatidae as outlined in the introductory chapters of this book. Lacking venom glands, these spiders first thoroughly wrap their prey and then kill it by grasping it with their palpal claws and pouring digestive juices over it. The chelicerae are little used in feeding, and their usual function of piercing and kneeding the prey is replaced by a greater use in wrapping silk. This thick wrapping of silk by which the spider enmeshes its captures may also be digested as feeding progresses (Opell 1979). There is a large diversity of web types in this group of spiders, although the group itself is rather small in species numbers (Lubin et al. 1982). Description. Carapace ovoid or abruptly narrowed toward front, dorsally flat to somewhat convex (Fig. 31). Eyes in 2 rows; anterior row of eyes straight or recurved, with anterior lateral eyes usually smaller than anterior median eyes; posterior row of eyes recurved, with posterior lateral eyes sometimes situated at or near carapace margin and sometimes situated on conspicuous tubercles. Legs short and stout to long and slender, sometimes with conspicuous brushes of setae (Fig. 34); legs of males without sexual modifications. Abdomen convex dorsally (Fig. 19), often projecting anteriorly over carapace, with undivided cribellum, in females often with paired dorsal humps. Palpus of male sometimes with 1 or 2 ventral tubercles on femur, and usually with 1 or 2 stout dorsal macrosetae on tibia and patella; tegulum sometimes small and largely concealed by other bulbal sclerites, sometimes large and bulbous; median apophysis present or absent, sometimes possibly united with conductor; embolus long, hairlike, sometimes coiled around tegulum or median apophysis (Figs. 23, 29, 35); conductor often with long hornlike process distally (Figs. 24, 30); terminal apophysis absent. Epigynum small or large, sometimes broad and rectangular (Fig. 22), usually with mesal prominence, which may be continuous with posterior plate; spermathecae small, bulbous (Fig. 33), or undifferentiated from copulatory tubes, sometimes double. Comments. Opell (1979) lists and discusses several characters thought to be unique to members of the Uloboridae. These include the loss of venom glands, the possession of a tidy row of perpendicular macrosetae on the ventral surface of tarsi IV, the presence of 2 stridulatory setae near the tip of the male palpal cymbium, the presence of a row of prolateral trichobothria on leg femora III and IV (and a similar prolateral row on femur II), and the possession of robust tracheae that extend into the cephalothorax. A world fauna of 19 genera and 243 species has been catalogued (Platnick 2002). Muma and Gertsch (1964) revised the four genera and 15 species represented in the United States and Canada. Opell (1983) provided a checklist of the Uloboridae in North, Central, and South America. Two genera and three species

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are represented in Canada. A population of a pantropical species, Zosis geniculata (Olivier), has been found in a greenhouse in southern Ontario. The Asian species Octonaba sinensis (Simon) has been found in greenhouses in upstate New York; it may eventually also be found in Canada. Further observation is needed to determine whether or not these aliens are to be treated as part of the Canadian fauna.

Key to genera of Uloboridae 1.

Posterior lateral eyes large and situated on prominent tubercles. Carapace abruptly narrowed toward front . . . . . . . . . . Hyptiotes Walckenaer (p. 34)

1'.

Posterior lateral eyes similar in size to other eyes and not situated on tubercles. Carapace gradually narrowed toward front (Fig. 31) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Uloborus Latreille (p. 40)

Clé des genres d'Uloboridae 1.

Yeux latéraux postérieurs plus grands que les autres yeux et situés sur des tubercules proéminents. Rétrécissement abrupt du céphalothorax dans sa partie antérieure. . . . . . . . . . . . . . . . . . . . . . Hyptiotes Walckenaer (p. 34)

1'.

Yeux latéraux postérieurs de la même dimension que les autres yeux; ne se trouvant pas sur des tubercules. Rétrécissement graduel du céphalothorax dans sa partie antérieure (fig. 31) . . . . . . . . . . . Uloborus Latreille (p. 40)

Genus Hyptiotes Walckenaer Members of the genus Hyptiotes build webs in the lower branches of coniferous trees, often among dead twigs in the tree's interior, although occasional specimens may be found in the underbrush or even on cliffs or in ravines. The webs are triangular in form, being three 45°–60° sectors of an orb. There are four radii, with 10 or more sticky lines laid across them. The radii arise from the bridge line, on which the spider hangs, venter uppermost, with its front legs pulling the web taut. Release of the tension is cued by the presence of an insect prey in the web, and the spider feeds on both prey and silk. Egg sacs are attached to the twigs in late summer and early autumn. Spiderlings emerge in the spring. Description. Total length 2.0–5.0 mm. Carapace approximately as wide as long, rather low, abruptly narrowed anteriorly, deeply indented at posterior margin; front broadly convex. Anterior row of eyes nearly straight (dorsal view), with lateral eyes minute, situated at lateral margins of carapace; posterior row of eyes strongly recurved (dorsal view), with median eyes situated near lateral margins of

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carapace and lateral eyes situated on conspicuous tubercles, also at lateral margins of carapace. Chelicerae small; promargin of fang furrow with 3 teeth, and retromargin with 2 teeth. Legs short, rather stout, in males with strong macrosetae; femur I equal to or shorter than carapace length; leg IV with calamistrum; calamistrum composed of single row of curved bristles. Abdomen convex dorsally (less so in males), overhanging carapace, in females often with paired dorsal setose tubercles, with large undivided cribellum. Palpus of male with cymbium small, hairy; tegulum large; conductor and median apophysis large, extending full length of genital bulb; conductor with long curved hornlike distal process (Figs. 24, 30); median apophysis prolateral in position; (Note: Opell's (1979) labelling of conductor and median apophysis was reversed by Coddington (1990a)); embolus long, hairlike, arising near base of genital bulb and making 1.5 turns around median apophysis, with tip lying on small spur at distal extremity of conductor (Figs. 23, 29). Epigynum broad, rectangular, with rounded or angulate median tubercle (Figs. 20–22, 25–27); posterior surface with large distinct plate, which extends to ventral surface where it forms part of the epigynal tubercle; copulatory tubes long, slender, convoluted; spermathecae not differentiated from copulatory tubes; accessory glands small to large, round. Comments. Members of the genus Hyptiotes are distinguished from those of other uloborid genera by the abruptly narrowed carapace, by the straight anterior eye row, and the short first femur. Thirteen world species of Hyptiotes are catalogued, most of these being tropical. Four species are represented in North America, two in Canada. Muma and Gertsch (1964) revised the North American species, and Opell (1979) reviewed the world representatives.

Key to species of Hyptiotes 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2(1). Conductor process distinctly broad (Figs. 23, 24) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cavatus (Hentz) (p. 36) 2'.

Conductor process more slender (Figs. 28–30) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gertschi Chamberlin & Ivie (p. 38)

3(1'). Posterior plate of epigynum little visible in ventral view (Fig. 22) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cavatus (Hentz) (p. 36) 3'.

Posterior plate of epigynum clearly visible in ventral view (Fig. 27) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gertschi Chamberlin & Ivie (p. 38)

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Clé des espèces d'Hyptiotes 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2(1). Projection du conducteur nettement élargie (figs. 23, 24) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cavatus (Hentz) (p. 36) 2'.

Projection du conducteur plutôt étroite (figs. 28–30) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gertschi Chamberlin & Ivie (p. 38)

3(1'). Plaque postérieure de l'épigyne peu visible en vue latérale (fig. 22) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cavatus (Hentz) (p. 36) 3'.

Plaque postérieure de l'épigyne nettement visible en vue latérale (fig. 27) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gertschi Chamberlin & Ivie (p. 38)

Hyptiotes cavatus (Hentz) Triangle Weaver Figs. 19–24; Map 1

Cyllopodia cavata Hentz, 1847: 466, fig. 3 (pl. 30). Hyptiotes americanus Wilder, 1875:641, figs. 1–10. Hyptiotes cavatus: Emerton 1888:456, figs. 2–2k (pl. 11); Kaston 1948:514, figs. 1959–1963 (pl. 105), 1980–1984 (pl. 106), 2078 (pl. 138); Muma and Gertsch 1964:13, figs. l, 6–11, 13–17; Opell 1979:485, figs. 55–61, 63, 64; 1983:97, figs. 1–10. Male. Total length 2.00, 2.39 mm; carapace 1.00, 1.03 mm long, 0.83, 1.00 mm wide (2 specimens measured). Carapace brownish, with indistinct pale midstripe, covered with short scales and hairs. Legs brown, slender, with numerous short stout macrosetae dorsally and prolaterally on tibia I; femur III with single row of long trichobothria on dorsal and prolateral surfaces. Abdomen variable in color, usually with small paired tubercles; tubercles with many stiff dark setae. Process of conductor broad (Figs. 23, 24). Female. Total length 3.32, 3.42 mm; carapace 1.06, 1.20 mm long, 1.15, 1.16 mm wide (2 specimens measured). Structure and color essentially as in male, but carapace less narrowed at front, abdomen more convex dorsally, legs shorter, stouter, and with fewer macrosetae. Epigynum with posterior plate slender and little visible in ventral view (Figs. 20–22); copulatory tubes slender, convoluted; spermathecae continuous with copulatory tubes. Range. Wisconsin to Quebec, south to eastern Texas and Florida.

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Figs. 19–24. Hyptiotes cavatus. 19, female abdomen, lateral view; 20–22, epigynum: 20, posterior view; 21, lateral view; 22, ventral view; 23, 24, palpus of male: 23, retrolateral view; 24, detail of conductor. con, conductor; e, embolus; pp, posterior plate.

Comments. Specimens of H. cavatus are distinguished from those of other species in the genus by the broad conductor process in males and by the slender posterior plate of the epigynum. Biology. Adults of H. cavatus appear in August, and eggs are deposited from early September. The egg sacs are plano-convex, 6–8 mm long, oval in outline,

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Map 1. Collection localities of Hyptiotes cavatus.

and attached to a twig near the web (Kaston 1948). A description of the web and of the typical habitats are given under the heading “Cribellate orb webs”. Ultrastructure and various properties of the silk were investigated by Opell (1987a, 1989, 1994), Opell et al. (1990), and Eberhard and Pereira (1993). Opell (1982a) studied the ontogeny of the cribellum, calamistrum, and ventral comb, and (Opell 1983) detailed the anatomy of the complex external female genitalia. Opell (1984a, 1984b) reported the resistance to desiccation and the winter protection of the egg sacs. He also (Opell 1984c, 1988a) investigated the relationships between the eyes and certain features of the carapace and (Opell 1989) reported on weight distribution in the spider's body.

Hyptiotes gertschi Chamberlin & Ivie Figs. 25–30; Map 2

Hyptiotes gertschi Chamberlin and Ivie, 1935:12, figs. 38, 39; Muma and Gertsch 1964:15, figs. 19, 24–30; Opell 1979:454, figs. A–D (pl. 4). Male. Total length 2.63 ± 0.31 mm; carapace 1.03 ± 0.07 mm long, 1.09 ± 0.05 mm wide (10 specimens measured). Carapace yellowish brown, sometimes with paler or darker spots and stripes. Abdomen pale yellowish brown, often with

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Figs. 25–30. Hyptiotes gertschi. 25–27, epigynum: 25, posterior view; 26, lateral view; 27, ventral view; 28–30, palpus of male: 28, detail of conductor; 29, prolateral view; 30, retrrolateral view. con, conductor; e, embolus; pp, posterior plate.

distinct dark markings and with white stripe at sides. Process of conductor slender (Figs. 28–30). Female. Total length 3.34 ± 0.40 mm; carapace 1.13 ± 0.11 mm long, 1.28 ± 0.11 mm wide (10 specimens measured). Coloration much as in male. Abdomen usually strongly convex dorsally, with second pair of tubercles prominent. Epigynum (Figs. 25–27) with posterior plate large, distinctly visible in ventral view.

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Map 2. Collection localities of Hyptiotes gertschi.

Range. Southernmost Alaska to Newfoundland, south to California and Pennsylvania. Comments. Specimens of H. gertschi are distinguished from those of other species in the genus by the slender process on the palpal conductor of males and by the large posterior plate of the epigynum. Biology. Webs of individuals of H. gertschi may be abundant among the dead interior branches near the bottom of pine trees. Additional habitats, in the western part of the range, are cliff faces, ravines, and bridges (Muma and Gertsch 1964).

Genus Uloborus Latreille Members of the genus Uloborus build fully developed orb webs having a sticky spiral. The web is usually horizontal. Opell (1979) illustrates the two axial strands to which puffs of fine cribellate fibrils are added from the cribellar spigots and placed by the calamistrum. Junctions of the sticky spirals with radii are weakly attached by the cribellate fibrils, and the struggles of a prey in the web can cause slippage at the junctions, which in turn engages additional sticky spirals. A stabilimentum of some type is often added to the web, and usually takes the form of a slender band of silk which extends across the hub with a small inter-

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ruption at that point. Opell (1979) summarizes information to show that young spiderlings in which the cribellum and calamistrum have not yet become functional construct a sort of sheet web. After the temporary spiral has been constructed, the young spider, unable to spin a sticky spiral, attaches numerous fine secondary radii to the hub and allows them to drift on air currents. Some of these radii eventually find attachment to the primary radii, to the accessory spiral, or to other secondary radii and this accounts for the sheet-like nature of the webs. Mature males of some genera also lack a cribellum and calamistrum, and the webs of these individuals are like those of the young. Egg sacs are suspended in the web. Description. Total length 2.1–4.7 mm. Carapace (Fig. 31) ovoid in outline, gradually narrowed toward front, somewhat convex dorsally, dusky brown to black, often with pale median stripe from front to posterior margin, with many recumbent setae. Anterior row of eyes recurved, and posterior row strongly recurved; anterior lateral eyes smaller than other eyes. Legs rather long and slender; leg I longest, in juveniles and adult females with tufts or brushes of setae (Fig. 34); basitarsus IV with calamistrum; leg I with many trichobothria. Abdomen convex dorsally, in females with paired dorsal tubercles; cribellum large, undivided. Palpus of male with femoral tubercle ventrally; tegulum circular (Fig. 35); conductor semi-circular, largely concealing tegulum; embolus hairlike distally, making one turn around tegulum (Fig. 35); median apophysis lost (or combined with conductor). Epigynum small, with mesal prominence, and with paired prominences at posterior margin (Fig. 32). Spermathecae small, bulbous, with slender fertilization ducts (Fig. 33). Comments. Individuals of Uloborus spp. can be distinguished from those of other uloborid genera by the ovoid carapace, by the strongly recurved posterior row of eyes, by the presence of many trichobothria on leg I, and by the presence, in females, of a tuft of setae on tibia I. A world fauna of about 30 species of Uloborus is known, of which five are recorded in North America. A single species is represented in the Canadian fauna.

Uloborus glomosus (Walckenaer) Featherlegged Orbweaver Figs. 31–35; Map 3

Epeira glomosa Walckenaer, 1837:143. Phillyra mammeata Hentz, 1850:25, fig. 16 (pl. 3). Phillyra riparia Hentz, 1850: 26, fig. 17 (pl. 3). Uloborus plumipes: Emerton 1902:216, figs. 495–499.

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Figs. 31–35. Uloborus glomosus. 31, carapace of female, dorsal view; 32, epigynum; 33, spermathecae; 34, leg I; 35, palpus of male. con, conductor; e, embolus; spt, spermatheca; teg, tegulum.

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Map 3. Collection localities of Uloborus glomosus.

Uloborus americanus: Kaston 1948:513, figs. 1956–1958 (pl. 105), 1976–1979 (pl. 106), 2076, 2077 (pl. 137). Uloborus glomosus: Chamberlin and Ivie 1944:34; Muma and Gertsch 1964:23, figs. 40, 41, 44, 45, 66–70; Opell 1979:504, figs. A (pl. 7), 129, 130. Male. Total length 2.73 ± 0.13 mm; carapace 1.13 ± 0.07 mm long, 0.97 ± 0.09 mm wide (10 specimens measured). Carapace (Fig. 31) low, usually brownish to black, sometimes with narrow pale median band from front to posterior margin, usually with pale lateral margins. Leg I usually dusky brown; tibia I with numerous stout macrosetae; legs II–IV variably colored. Abdomen nearly flat dorsally, without tubercles. Palpal femur with prominent ventral tubercle; genital bulb (Fig. 35) nearly circular in ventral view, with conductor large, semi-circular, and terminating in stout pointed spur; embolus (Fig. 35) slender, hairlike, arising near tip of bulb and extending clockwise (left palpus, ventral view) around bulb in approximately one turn. Female. Total length 3.94 ± 0.46 mm; carapace 1.39 ± 0.19 mm long, 1.15 ± 0.10 mm wide (10 specimens measured). Coloring variable, essentially as in male. Carapace rather convex, ovoid in outline. Tibia I (Fig. 34) with dorsal and ventral brush of setae, lacking stout macrosetae. Abdomen high, strongly convex, 43

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with three pairs of setose tubercles. Epigynum (Fig. 32) with pair of blunt processes at posterior margin; spermathecae small, bulbous (Fig. 33). Range. Wisconsin to southern Quebec and Massachusetts, south to Texas and Florida, Central America, and the West Indies. Comments. Specimens of U. glomosus are distinguished from those of others in the genus Uloborus by the stout pointed spur on the conductor of males, and by the blunt epigynal processes and bulbous spermathecae. Biology. Individuals of U. glomosus build horizontal orb webs 10–15 cm in diameter. A meshlike hub is present, and the innermost sticky spirals are well separated, those toward the periphery being closer together than those inside (Emerton 1902, figs. 495–497). There may also be zigzag lines of loose silk across the centre or inside the innermost sticky spiral, as well as a linelike stabilimentum. Maturity is reached in May or early June, and eggs are laid in late June and in July (Kaston 1948). The egg sacs are fastened to a radius in the web; there may be 30–60 eggs in each sac (Gertsch 1979:34; Kaston 1948). The common habitat of U. glomosus is shady woods, usually in the dead lower branches of conifers, but sometimes across hollow stumps, among rocks, or even across the gutters of houses. Cushing and Opell (1990a, 1990b) investigated some possible predatoravoidance behaviors, and Opell (1987a, 1992) reported on the web-monitoring force exerted by U. glomosus during its hunting operation. Opell (1984a, 1984b) also gave preliminary data on the resistance to desiccation and characteristics of the silk in the egg sacs. Opell (1984c, 1988a, 1988b) investigated the relationship between eyes and carapace in U. glomosus, and (Opell 1989) gave data on weight distribution within the spider's body. Opell (1994) described factors affecting diameter of the axial fibers in cribellar threads.

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Family Tetragnathidae The elongate chelicerae and palp-coxal lobes, both organs protruding conspicuously to the front in most members of the Tetragnathidae, have given these spiders the common name “long-jawed” orb weavers. The body is often long and slender, as are the legs. The common habitats are moist meadows and ravines, and also the margins of lakes and streams. The web may be large, with many radii, or smaller, and, in the case of adults of at least one foreign genus, entirely lacking. The hub is bitten out after the frame and spiral threads are in place. Description. Carapace longer than wide (sometimes much longer), low, often yellowish, without setae. Eyes usually small and nearly uniform in size; lateral eyes on each side usually distinctly separated; tapetum tending toward reduction and loss in posterior median eyes and in lateral eyes. Chelicerae often as long as carapace or longer (Figs. 64, 115), with many strong teeth on both margins, in males sometimes with spur on anterior surface (Figs. 54, 63). Legs long, slender, usually with many long macrosetae (Figs. 44, 255), rarely without macrosetae; femora often with dorsal trichobothria. Abdomen long and slender, broadly elliptical or more spherical, rarely with paired anterolateral humps, often silvery and/or yellow in color. Palpus of male with embolus and conductor arising together laterally, then passing mesally and far distally, sometimes twisted together (Fig. 69); tegulum smooth, shiny, spherical or nearly so; median apophysis and terminal apophysis absent; paracymbium basal, short and robust or long and slender, sometimes lobed, branched, or hooked. Epigynum (Figs. 37, 56, 200) often without sclerotized plate or median septum, sometimes with transverse slit; spermathecae (Figs. 57, 237, 260) often bilobed, weakly sclerotized, situated at level of book lungs. Piriform silk glands sometimes tripartite or bipartite (Kovoor 1990). Comments. Members of the family Tetragnathidae are a rather diverse group of orb weavers of small to large size. They are difficult to diagnose, though apparently monophyletic (Hormiga et al. 1995, Griswold et al. 1998). A number of characteristics are evident among them: long toothed chelicerae, lack of sclerotization in the epigynum, possession of femoral trichobothria (also found in representatives of at least some Uloboridae), and reduction and loss of the tapetum in certain pairs of eyes. The best available characters are those proposed by Hormiga et al. (1995) from the male palpus, namely, the presence of sclerites at the tip of the tegulum, the embolus and conductor arising and passing together to the tip of the palpus, and the loss of the median apophysis. The Tetragnathidae are represented by a world fauna of 58 genera and 979 species. Ten genera and 37 species are represented in North America (Levi 1980, 1981, Platnick 1989, 1993, 2002), six genera and 25 species in Canada.

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Key to genera of Tetragnathidae l.

Leg femora, in part, with dorsal trichobothria near base . . . . . . . . . . . 2

1'.

Leg femora without dorsal trichobothria. . . . . . . . . . . . . . . . . . . . . . . 5

2(1).

Tracheal spiracle situated approximately one-third distance from spinnerets to book-lung openings (Fig. 37) . . . Glenognatha Simon (p. 47)

2'.

Tracheal spiracle situated immediately anterior to spinnerets . . . . . . . 3

3(2').

Femur IV with cluster of long trichobothria prolaterally near base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Leucauge White (p. 50)

3'.

Femur IV without cluster of long trichobothria. . . . . . . . . . . . . . . . . . 4

4(3').

Abdomen slender, longer than cephalothorax (Figs. 52, 55). Sternum not extended between bases of leg coxae . . . Tetragnatha Latreille (p. 53)

4'.

Abdomen elliptical, approximately as long as cephalothorax (Figs. 166, 225). Sternum extended between bases of leg coxae. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pachygnatha Sundevall (p. 88)

5(1').

Abdomen somewhat flattened dorsally, white with small indistinct black spots (Fig. 245) . . . . . . . . . . . . . Metellina Chamberlin & Ivie (p. 107)

5'.

Abdomen plump dorsally, approximately as high as long, brownish with paired large dark spots (Figs. 255, 257) . . . . . Meta C.L. Koch (p. 116)

Clé des genres de Tetragnathidae l.

Partie dorsale d’au moins un fémurs des pattes munie de trichobotries . .....................................................2

1'.

Fémurs des pattes sans trichobotries . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2(1).

Stigmate trachéen situé environ au tiers de la distance entre les filières et la trachée pulmonaire (fig. 37). . . . . . . . Glenognatha Simon (p. 47)

2'.

Stigmate trachéen situé tout juste en avant des filières . . . . . . . . . . . . 3

3(2').

Base du fémur IV pourvue d'une touffe prolatérale de longues trichobotries . . . . . . . . . . . . . . . . . . . . . . . . . . . Leucauge White (p. 50)

3'.

Base du fémur IV sans longues trichobotries . . . . . . . . . . . . . . . . . . . 4

4(3').

Abdomen élancé, plus long que le céphalothorax (figs. 52, 55). Sternum qui ne se prolonge pas entre la base des coxas des pattes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tetragnatha Latreille (p. 53)

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4'.

Abdomen plus arrondi, de longueur semblable au céphalothorax (figs. 166, 225). Sternum qui se prolonge entre la base des coxas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pachygnatha Sundevall (p. 88)

5(1').

Surface dorsale de l'abdomen plutôt aplatie, abdomen de couleur blanchâtre portant des petites taches noires plus ou moins définies (fig. 245) . . . . . . . . . . . . . . . . . . Metellina Chamberlin & Ivie (p. 107)

5'.

Surface dorsale de l'abdomen bombée, abdomen presque aussi haut que long et de couleur brunâtre, arborant une paire de grosses taches sombres (figs. 255, 257) . . . . . . . . . . . . . . . . . . . . Meta C.L. Koch (p. 116)

Genus Glenognatha Simon Members of the genus Glenognatha are small inhabitants of meadows, abandoned fields, crop plantings, dry stream beds, and similarly exposed situations. The web is horizontal and suspended only a few centimetres above the ground. The abdomen of these spiders is spherical and shiny (Figs. 36, 37). The tracheal spiracle is situated nearly one-third the distance from spinnerets to book lungs; the trachea itself is specialized by subdivision into two large trunks, each of which then splits into numerous fine tubes running anteriorly and laterally within the body (Fig. 42). Description. Total length 1.4 to 5.4 mm. Carapace smooth, without setae, orange or yellowish orange. Eyes small, in two rows; posterior row straight or nearly so; lateral eyes of each side touching. Chelicerae (Figs. 38, 43) long, stout, divergent distally or essentially straight, with three teeth on anterior margin of fang furrow, four on posterior margin, sometimes with small distal spur on anterior surface. Legs thin, pale orange, without dark bands, without macrosetae (Fig 36); bases of femora with one to three dorsal trichobothria. Abdomen spherical, smooth, with alternating paired light and dark areas (Fig. 36); venter indistinctly darkened mesally; tracheal spiracle situated nearly one-third the distance from spinnerets to book lungs (Fig. 37). Palpus of male (Figs. 39–41) with spherical tegulum and short embolus and conductor; embolus and conductor twisted together (Fig. 41); median apophysis lacking; paracymbium of one branch, slender, somewhat curved or sinuous, movably attached to cymbium (Fig. 40). Epigynum slitlike, little sclerotized (Fig. 37); spermathecae small, round or elliptical, well separated, connected by sac (Fig. 42). Comments. Members of the genus Glenognatha are distinguished from those of other tetragnathid genera by the spherical abdomen, the anterior placement of the tracheal spiracle, the spherical tegulum, and the slender paracymbium. The genus comprises a world fauna of about 12 species. Three of these occur in North America, one in Canada.

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Glenognatha foxi (McCook) Figs. 36–43; Map 4

Theridium foxi McCook, 1894: 402, fig. 1a, lb, 1c (pl. 29). Mysmena bulbifera Banks, 1896a:66. Diplocephalus crumbi Petrunkevitch, 1925: 171, figs. 1, 2 (pl. 8). Glenognatha foxi: Crosby and Bishop 1928: 1055; Levi 1980:68, figs. 272–284. Mimognatha foxi: Kaston 1948:264, figs. 834, 835 (pl. 40). Male. Total length 1.68 (1.58–1.83) mm; carapace 0.69 (0.60–0.83) mm long, 0.58 (0.50–0.65) mm wide (6 specimens measured). Carapace orange, smooth. Chelicerae long, little divergent distally, with small spur distally on anterior surface (Fig. 38). Legs yellow. Abdomen spherical, hairy, yellow to pale orange, sometimes with paired silvery spots alternating with dark areas on posterior half. Palpus with large spherical tegulum, and with short twisted embolus and conductor (Figs. 39–41); paracymbium slender, bulbous at tip, somewhat sinuous (Fig. 40). Female. Total length 1.49, 1.65 mm; carapace 0.58, 0.68 mm long, 0.52, 0.52 mm wide (2 specimens measured). Coloration as in male. Chelicerae short-

Map 4. Collection localities of Glenognatha foxi.

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Figs. 36–43. Glenognatha foxi. 36, female, dorsal view; 37, female, ventral view; 38, eyes and chelicerae of male, anterior view; 39–41, palpus of male: 39, ventral view; 40, retrolateral view; 41, embolus and conductor; 42, epigynum and tracheae; 43, chelicera of female. con, conductor; e, embolus; epig, epigynum; pc, paracymbium; spt, spermatheca; teg, tegulum; trsp, tracheal spiracle.

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er and less divergent than in male. Epigynum situated short distance posterior to book lungs (Fig. 37); spermathecae small, round, well separated, connected by angular membranous sac (Fig. 42). Range. Wisconsin, southern Ontario, and Massachusetts, south to California, Panama, and Jamaica. Comments. Specimens of G. foxi differ from those of other tetragnathids by the characters given to diagnose the genus Glenognatha. Biology. Collections of G. foxi have been made from marshes, both salty and fresh, and from the edges of ponds, as well as less moist habitats such as dry lake beds, among stones, and fields of corn. Barrows (1919) described the webs and mating, stating that the latter occurred in June.

Genus Leucauge White Members of the genus Leucauge are builders of large webs in low shrubs, hedges, orchard trees, and similar habitats. Webs are often horizontal or nearly so, and have a great number of radii and spirals. There may be a barrier of irregular threads below the orb. Males and females differ little in size, and the legs of males exhibit no sexual modifications. The common body coloring is silvery. Description. Total length 3.2–10.0 mm. Carapace (Fig. 44) broad posteriorly, somewhat narrowed at sides anteriorly; dorsal groove deep, transverse, round or ovoid, with transverse depression anterior to it. Eyes subequal in size; posterior row of eyes straight or somewhat procurved. Chelicerae stout (Fig. 45), somewhat swollen on anterior surface, with 3 teeth on promargin and 3 or 4 teeth on retromargin. Legs long, slender; femur IV with cluster of long trichobothria prolaterally near base (Fig. 46); legs I longest, followed in sequence by II, IV, and III. Abdomen (Fig. 44) broadly elliptical (females) or somewhat tapered posteriorly (males), silvery dorsally. Palpus of male (Figs. 50, 51) with large bulging tegulum, and with large terminal conductor and long fine embolus; subtegulum appressed to tegulum; embolus hidden by conductor, broad at base, hairlike distally; paracymbium small, hooklike, situated at base of cymbium. Epigynum (Figs. 47, 48) with median plate, sometimes with pointed prominence; spermathecae (Fig. 49) kidney-shaped, thin-walled, touching at midline. Comments. Characters by which members of the genus Leucauge can be distinguished from those of other genera are the cluster of long trichobothria on femur IV, the broadly elliptical silvery abdomen, the transverse depression anterior to the dorsal groove, the small hooklike paracymbium, and the hidden hairlike distal part of the embolus. A world fauna of about 30 species is recognized. Two species are represented in North America, of which only Leucauge venusta (Walckenaer) occurs in Canada.

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Leucauge venusta (Walckenaer) Orchard Orbweaver Figs. 44–51; Map 5

Epeira venusta Walckenaer, 1841:90. Epeira hortorum Hentz, 1847:477, fig. 19 (pl. 31). Leucauge venusta: F.O. Pickard-Cambridge 1903:441, figs. 1, 2 (pl. 42); Kaston 1948:265, figs. 836, 837 (pl. 40), 843–846 (pl.41); Levi 1980:25, figs. 44–59, Plates 3, 4. Male. Total length 3.65, 3.90, 3.98 mm; carapace 1.63, 1.66, 1.74 mm long, 1.25, 1.33, 1.65 mm wide (3 specimens measured). Carapace and legs yellowish green, sometimes with darker stripes along midline and on lateral areas. Lateral eyes of each side touching. Abdomen (Figs. 44, 46) approximately twice as long as wide, somewhat tapered posteriorly, silvery dorsally; with dark line at middle from which four similar lines branch and extend posteriorly; venter with large red or orange spot near middle, and with pair of small silvery triangles. Palpal tibia (Fig. 51) distinctly longer than cymbium; tegulum occupying much of bulb (ventral view), with seminal duct visible through integument; median apophysis absent; conductor long, broad, with two slender points extending beyond tip of

Map 5. Collection localities of Leucauge venusta.

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Figs. 44–51. Leucauge venusta. 44, female, dorsal view; 45, eyes and chelicerae, anterior view; 46, female, ventral view; 47, 48, epigynum: 47, ventral view; 48, posterior view; 49, spermathecae; 50, 51, palpus of male: 50, retrolateral view; 51, ventral view. con, conductor; cym, cymbium; pc, paracymbium; sd, sperm duct; teg, tegulum; tib, tibia.

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cymbium (Fig. 51); embolus with slender distal part extending to tip of conductor; paracymbium small, curved, somewhat flattened (Figs. 50, 51). Female. Total length 5.75 ± 1.24 mm; carapace 2.13 ± 0.39 mm long, 1.74 ± 0.31 mm wide (10 specimens measured). General structure and coloration essentially as in male. Abdomen broadly elliptical in outline. Epigynum with somewhat raised anterior margin and nearly flat parallel-sided median septum (Figs. 47, 48); spermathecae long, kidney-shaped, somewhat rugose, touching at midline (Fig. 49). Range. Minnesota to southern Ontario and New Hampshire, south to Panama; also coastal California and northern Arizona. Comments. Specimens of L. venusta are distinguished from those of other species in the genus by the white triangular marks in the abdominal venter, the long palpal tibia and long broad conductor of males, and the nearly flat median septum of females. Individuals superficially resemble those of some species of Mangora, but possess a cluster of long trichobothria on femur IV rather than on tibia III. Males of L. venusta also lack the coxal spur found on leg I of Mangora spp., and also lack a median apophysis. The carapace of both sexes in L. venusta is much lower than in specimens of Mangora spp. Biology. The preferred habitat appears to be low shrubs and the lower parts of trees in wooded areas, particularly where moisture is abundant. The web is horizontal or nearly so, and has an irregular barrier of threads below it. There is a small hole at the hub, a broad free zone, and 30 or more radii and 60 or more sticky spirals (Levi 1980). Mature males have been recorded from late May to early July, mature females in June and July. Levi (1980) describes the egg sac as made of “loose, fluffy orange-white silk, 8–9 mm in diameter”.

Genus Tetragnatha Latreille Members of the genus Tetragnatha are moderately large inhabitants of trees, shrubs, and tall grass in meadows or along the margins of lakes and streams. Some build their webs over running water, where emerging aquatic insects are the main prey. Some of these spiders may stand at the hub of their webs by day as well as night; others may be crepuscular. Some may also be found closely appressed to a grass stem near the web, extending legs I and II forward along the stem and III and IV backward in the same way, thus achieving a degree of camouflage. The webs are usually inclined from the vertical, sometimes horizontal, and may be 30 cm or more in diameter. The hub is usually open, and there is a well-defined free zone and narrow attachment zone. Description. Total length 3.8–13.3 mm. Carapace longer than wide, somewhat flattened, without setae, yellowish, sometimes with indistinct dark median band. Eyes small, ringed with black pigment; lateral eyes on each side usually 53

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distinctly separated, sometimes more so than are the anterior median eyes from posterior median eyes. Chelicerae stout (Figs. 53, 54), as long as carapace or longer, with many strong teeth on both anterior and posterior margins of fang furrow, in males with stout curved spur distally on anterior surface (Fig. 54). Legs pale yellowish or brownish, long, slender, with many long macrosetae; femora with several long dorsal trichobothria near base; male legs I and II lacking sexual modifications. Abdomen (Figs. 52, 55) long, cylindrical or nearly so, sometimes projecting posteriorly beyond spinnerets, often silvery, usually with dorsal pattern of gray or black bands having scalloped lateral margins (Figs. 115, 118); venter pale or with dark longitudinal band. Palpus of male (Fig. 69) with nearly spherical tegulum; embolus (Fig. 69) long, slender, coiled and ridged at base, straight or somewhat sinuous distally; conductor long, straight or sinuous, enfolding embolus, with complex tip; paracymbium (Fig. 69) long, slender, loosely attached to cymbium; median apophysis absent. Epigynum (Figs. 56, 65) lacking sclerotization, with copulatory openings at posterior end; spermathecae (Figs. 56, 57) usually bilobed, moderately large, weakly sclerotized, situated near level of book lungs, usually well separated but sometimes nearly touching at midline. Comments. Members of the genus Tetragnatha are distinguished from those of other tetragnathid genera by the greatly elongated chelicerae, long slender abdomen, and by the presence of hooks or flattened lobes at the tip of the conductor. The broad separation of the lateral eyes on each side in representatives of many species is also unusual. Representatives of the genus Tetragnatha share with those of Leucauge, Glenognatha, and Pachygnatha (these together comprising a possible subfamily Tetragnathinae) the loss of the tapetum from the posterior median eyes, enlarged male chelicerae, constricted cymbium, elongated articulated paracymbium, loss of epigynal sclerotization, and loss of fertilization ducts (Hormiga et al. 1995). The genus is represented widely in Europe, Africa, Asia, and the Americas. Bonnet (1959) catalogues more than 200 world species. Levi (1981) treats 15 North American species, of which 12 are represented in Canada.

Key to species of Tetragnatha 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2(1).

Lateral eyes on each side farther apart than medians on each side (as measured from eye centres) (Figs. 53, 54) . . . . . . . . . . . . . . . . . . . . . 3

2'.

Lateral eyes on each side as far apart as medians or closer together (Figs. 98, 99, 107, 108, 117). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

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3(2).

Abdomen with distinct pointed extension posteriorly beyond spinnerets (Figs. 52, 55) . . . . . . . . . . . . . . . . . . . . . . . . caudata Emerton (p. 60)

3'.

Abdomen without pointed extension posteriorly beyond spinnerets . . 4

4(3').

Conductor with one or more high thin ridges at base (Figs. 77, 86, 95) .....................................................5

4'.

Conductor without ridges at base (Fig. 68) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vermiformis Emerton (p. 62)

5(4).

Conductor strongly hooked at tip (Fig. 77) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pallescens F.O. Pickard-Cambridge (p. 64)

5'.

Conductor not strongly hooked (Figs. 86, 95). . . . . . . . . . . . . . . . . . . 6

6(5'.)

Tip of conductor with distinct basal constriction (Fig. 86) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . straminea Emerton (p. 67)

6'.

Tip of conductor without basal constriction (Fig. 95) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . shoshone Levi (p. 69)

7(2').

Tip of conductor thick, constricted at base (Figs. 104, 113, 122, 132). . .....................................................8

7'.

Tip of conductor slender, not distinctly constricted at base (Figs. 141, 155, 164) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

8(7).

Tip of conductor pointed (Figs. 104, 113). . . . . . . . . . . . . . . . . . . . . . 9

8'.

Tip of conductor rounded (though base may bear minute point (Figs. 122, 132) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

9(8).

Point at tip of conductor curved (Fig. 104) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . extensa (Linnaeus) (p. 71)

9'.

Point at tip of conductor straight (Fig. 113) . . . laboriosa Hentz (p. 74)

10(8').

Lateral eyes on each side closer together than medians on same side (Figs. 116, 117). Body in life yellow or orange. Paired macrosetae on leg tibiae usually short, approximately as long as tibial thickness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . versicolor Walckenaer (p. 76)

10'.

Lateral eyes on each side approximately as far apart as medians on same side (Figs. 125, 126). Body in life green, often with red markings. Paired macrosetae on leg tibiae 5–8 times as long as tibial thickness (Fig. 131) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viridis Walckenaer (p. 78)

11(7').

Paracymbium tip angled laterally (Fig. 142). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . guatemalensis O. Pickard-Cambridge (p. 81)

11'.

Paracymbium tip not angled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

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12(11'). Palpal tibia longer than cymbium (Fig. 156). Chelicerae usually longer than carapace (Fig. 144). Conductor with flange at base (Figs. 153, 154) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . elongata Walckenaer (p. 83) 12'.

Palpal tibia shorter than cymbium. Chelicerae shorter than carapace. Conductor without flange at base (Fig. 164) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . dearmata Thorell (p. 85)

13(1')

Lateral eyes on each side farther apart than medians on each side (Figs. 53, 62, 71, 80, 89) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

13'.

Lateral eyes on each side as far apart as medians or closer together (Figs. 98, 107, 117, 125, 135, 145, 158) . . . . . . . . . . . . . . . . . . . . . . 18

14(13). Abdomen with distinct pointed extension posteriorly beyond spinnerets (Fig. 55) . . . . . . . . . . . . . . . . . . . . . . . . . . . . caudata Emerton (p. 60) 14'.

Abdomen without pointed extension. . . . . . . . . . . . . . . . . . . . . . . . . 15

15(14'). Spermathecae elongate, slender, oriented longitudinally (Figs. 66, 67) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vermiformis Emerton (p. 62) 15'.

Spermathecae bulbous, oriented obliquely or transversely (Figs. 75, 76, 84, 85, 93, 94) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

16(15'). Spermathecae on each side connected by large lobe (Figs. 75, 76) . . . . . . . . . . . . . . . . . . . . . . . . pallescens F.O. Pickard-Cambridge (p. 64) 16'.

Spermathecae on each side connected by slender tube (Figs. 84, 85), or touching (Figs. 93, 94) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

17(16'). Spermathecae on each side connected by slender tube (Fig. 85) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . straminea Emerton (p. 67) 17'.

Spermathecae on each side touching (Fig. 94) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . shoshone Levi (p. 69)

18(13'). Spermathecae side by side, oriented longitudinally (Figs. 139, 140) . . . . . . . . . . . . . . . . . . . . . . . guatemalensis O. Pickard-Cambridge (p. 81) 18'.

Spermathecae not side by side, not oriented longitudinally . . . . . . . . 19

19(18'). Anterior spermatheca on each side concealed by large pouch (Fig. 112) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . laboriosa Hentz (p. 74) 19'.

Anterior spermatheca not concealed by pouch . . . . . . . . . . . . . . . . . 20

20(19'). Anterior arm of spermatheca longer than posterior (Figs. 149, 150). Chelicerae usually longer than carapace (Figs. 144, 147, 152) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . elongata Walckenaer (p. 83) 20'.

56

Anterior arm of spermatheca equal in length to posterior arm, or shorter (Figs. 102, 120, 129, 162) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

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21(20'). Anterior arm of spermatheca shorter than posterior arm (Figs. 102, 103). Venter of abdomen with median black band, which is flanked by pair of narrow silvery bands . . . . . . . . . . . . . . . . . extensa (Linnaeus) (p. 71) 21'.

Anterior arm of spermatheca approximately equal in length to posterior arm (Figs. 120, 129, 162). Venter of abdomen usually without median black band flanked by narrow silvery bands . . . . . . . . . . . . . . . . . . . 22

22(21'). Anterior arm of spermatheca thicker than posterior arm (Fig. 163) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . dearmata Thorell (p. 85) 22'.

Anterior arm of spermatheca approximately equal in thickness to posterior arm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

23(22'). Paired macrosetae on tibia I short, approximately as long as tibial thickness. Body in life pale orange or pale yellow. Dorsal color bands on abdomen usually scalloped at lateral margins (Figs. 115, 118) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . versicolor Walckenaer (p. 76) 23'.

Paired macrosetae on tibia I 5–8 times as long as tibial thickness (Fig. 131). Body in life green, often with red markings. Dorsal color bands on abdomen with straight lateral margins (Fig. 124) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viridis Walckenaer (p. 78)

Clé des espèces de Tetragnatha 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2(1).

Distance entre l'œil latéral antérieur et postérieur plus grande qu'entre l'œil médian antérieur et postérieur (mesurés de centre à centre) (figs. 53, 54). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2'.

Distance entre l'œil latéral antérieur et postérieur égale ou plus petite qu'entre l'œil médian antérieur et postérieur (figs. 98, 99, 107, 108, 117) .....................................................7

3(2).

Abdomen se terminant en une pointe qui se prolonge au-delà des filières (figs. 52, 55) . . . . . . . . . . . . . . . . . . . . . . . . caudata Emerton (p. 60)

3'.

Abdomen ne se terminant pas en pointe . . . . . . . . . . . . . . . . . . . . . . . 4

4(3').

Base du conducteur munie d'une ou plusieurs minces carènes proéminentes (figs. 77, 86, 95) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

4'.

Base du conducteur sans carènes (fig. 68) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vermiformis Emerton (p. 62)

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5(4).

Apex du conducteur formant un crochet prononcé (fig. 77) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pallescens F.O. Pickard-Cambridge (p. 64)

5'.

Apex du conducteur moins recourbé (figs. 86, 95) . . . . . . . . . . . . . . . 6

6(5'.)

Présence d'un étranglement marqué dans la partie terminale du conducteur (fig. 86) . . . . . . . . . . . . . . . . . . . . . . . . straminea Emerton (p. 67)

6'.

Absence d’étranglement dans la partie terminale du conducteur (fig. 95) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . shoshone Levi (p. 69)

7(2').

Apex du conducteur élargi, étranglé à la base (figs. 104, 113, 122, 132) .....................................................8

7'.

Apex du conducteur étroit, sans étranglement marqué à la base (figs. 141, 155, 164) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

8(7).

Apex du conducteur en pointe (figs. 104, 113) . . . . . . . . . . . . . . . . . . 9

8'.

Apex du conducteur arrondi, quelquefois muni d'une petite pointe située à la base (figs. 122, 132) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

9(8).

Extrémité du conducteur recourbée (fig. 104). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . extensa (Linnaeus) (p. 71)

9'.

Extrémité du conducteur droite (fig. 113) . . . . . laboriosa Hentz (p. 74)

10(8').

Distance entre l'œil latéral antérieur et postérieur plus grande qu'entre l'œil médian antérieur et postérieur (figs. 116, 117). Coloration jaune ou orangée (spécimens vivants). Paires de soies articulées du tibia des pattes plutôt courtes, de longueur comparable à l'épaisseur du tibia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . versicolor Walckenaer (p. 76)

10'.

Distance entre l'œil latéral antérieur et postérieur égale à la distance entre l'œil médian antérieur et postérieur (figs. 125, 126). Coloration verte arborant souvent des traits rouges (spécimens vivants). Paires de soies articulées du tibia des pattes de 5 à 8 fois plus longues que l'épaisseur du tibia (fig. 131) . . . . . . . . . . . . . . . . . viridis Walckenaer (p. 78)

11(7').

Apex du paracymbium formant un angle en vue latérale (fig. 142). . . . . . . . . . . . . . . . . . . . . . . . guatemalensis O. Pickard-Cambridge (p. 81)

11'.

Apex du paracymbium ne formant pas d'angle . . . . . . . . . . . . . . . . . 12

12(11'). Tibia du palpe plus long que le cymbium (fig. 156). Chélicères habituellement plus longs que le céphalothorax (fig. 144). Base du conducteur muni d'une mince projection latérale (figs. 153, 154) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . elongata Walckenaer (p. 83) 12'.

58

Tibia du palpe plus court que le cymbium. Chélicères plus courts que le céphalothorax. Base du conducteur sans une mince projection latérale (fig. 164) . . . . . . . . . . . . . . . . . . . . . . . . . . . dearmata Thorell (p. 85)

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13(1')

Distance entre l'œil latéral antérieur et postérieur plus grande qu'entre l'œil médian antérieur et postérieur (figs. 53, 62, 71, 80, 89). . . . . . . 14

13'.

Distance entre l'œil latéral antérieur et postérieur égale ou plus petite qu'entre l'œil médian antérieur et postérieur (figs. 98, 107, 117, 125, 135, 145, 158) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

14(13). Abdomen se teminant en une pointe qui se prolonge au-delà des filières (fig. 55) . . . . . . . . . . . . . . . . . . . . . . . . . . . . caudata Emerton (p. 60) 14'.

Abdomen ne se teminant pas en pointe. . . . . . . . . . . . . . . . . . . . . . . 15

15(14'). Spermathèques allongées et étroites, orientées longitudinalement (figs. 66, 67) . . . . . . . . . . . . . . . . . . . . . vermiformis Emerton (p. 62) 15'.

Spermathèques globuleuses, orientées dans le plan latéral ou oblique (figs. 75, 76, 84, 85, 93, 94) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

16(15'). De chaque côté, spermathèques reliées par un conduit renflé (figs. 75, 76) . . . . . . . . . . . . . . . . . . pallescens F.O. Pickard-Cambridge (p. 64) 16'.

De chaque côté, spermathèques reliées par un étroit conduit tubulaire (figs. 84, 85), ou spermathèques se touchant directement (figs. 93, 94). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

17(16'). De chaque côté, spermathèques reliées par un étroit conduit tubulaire (fig. 85) . . . . . . . . . . . . . . . . . . . . . . . . . . straminea Emerton (p. 67) 17'.

De chaque côté, spermathèques se touchant directement (fig. 94) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . shoshone Levi (p. 69)

18(13'). De chaque côté, spermathèques côte à côte, orientées dans le plan longitudinal (figs. 139, 140) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . guatemalensis O. Pickard-Cambridge (p. 81) 18'.

De chaque côté, spermathèques éloignées l'une de l'autre et orientées dans un plan différent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

19(18'). De chaque côté, spermathèque antérieure cachée par un renflement (fig. 112) . . . . . . . . . . . . . . . . . . . . . . . . . . . . laboriosa Hentz (p. 74) 19'.

De chaque côté, spermathèque antérieure bien visible . . . . . . . . . . . 20

20(19'). Partie antérieure de la spermathèque plus longue que la partie postérieure (figs. 149, 150). Chélicères habituellement plus longs que le céphalothorax (figs. 144, 147, 152) . . . . . elongata Walckenaer (p. 83) 20'.

Partie antérieure de la spermathèque de même longueur ou plus courte que la partie postérieure. (figs. 102, 120, 129, 162) . . . . . . . . . . . . . 21

21(20'). Partie antérieure de la spermathèque plus courte que la partie postérieure (figs. 102, 103). Partie ventrale de l'abdomen arborant une bande médiane noire, bordée de chaque côté par une étroite bande argentée. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . extensa (Linnaeus) (p. 71) 59

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Partie antérieure de la spermathèque de la même longueur ou presque que la partie postérieure (figs. 120, 129, 162). Partie ventrale de l'abdomen habituellement sans bande médiane noire et bandes argentées . . . . . 22

22(21'). Partie antérieure de la spermathèque plus large que la partie postérieure (fig. 163) . . . . . . . . . . . . . . . . . . . . . . . . . . . dearmata Thorell (p. 85) 22'.

Partie antérieure de la spermathèque de la même largeur ou presque que la partie postérieure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

23(22'). Paires de soies articulées du tibia I plutôt courtes, de longueur comparable à l'épaisseur du tibia. Coloration jaune pâle ou orange pâle (spécimens vivants). Marges des bandes de couleur de l'abdomen habituellement sinueuses (figs. 115, 118) . . . . . . . versicolor Walckenaer (p. 76) 23'.

Paires de soies articulées du tibia I de 5 à 8 fois plus longues que l'épaisseur du tibia (fig. 131). Coloration verte arborant souvent des traits rouges (spécimens vivants). Marges des bandes de couleur de l'abdomen droites (fig. 124) . . . . . . . . . . . . . . . . . . . . . viridis Walckenaer (p. 78)

Tetragnatha caudata Emerton Figs. 52–60; Map 6

Tetragnatha caudata Emerton, 1884:335, figs. 16, 22 (pl. 39); Kaston 1948:273, figs. 873, 874 (pl. 42); Levi 1981:310, figs. 140–148, plate 7(b,c). Male. Total length 6.51 ± 1.11 mm; carapace 1.88 ± 0.25 mm long, 1.06 ± 0.18 mm wide (10 specimens measured). Carapace yellowish or pale orange, sometimes with indistinct darker lines radiating from dorsal groove. Lateral eyes on each side farther apart than medians on each side (Fig. 54). Legs yellowish, unmarked. Abdomen long, slender, extended in point posteriorly beyond spinnerets (Fig. 52), silvery dorsally and on sides; venter somewhat paler or darker at midline. Conductor (Figs. 59, 60) with two high thin ridges at base, expanded in large hook at tip; tip abruptly narrowed, with minute spur at base. Female. Total length 9.63 ± 1.80 mm; carapace 2.10 ± 0.28 mm long, 1.22 ± 0.23 mm wide (10 specimens measured). Eyes, abdomen, and coloration as in male (Figs. 53, 55). Epigynum short, broad (Fig. 56); spermathecae small, connected by slender tube (Fig. 58). Range. British Columbia to Prince Edward Island, south to California, Central America, and Cuba.

60

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Figs. 52–60. Tetragnatha caudata. 52, female, lateral view; 53, eyes and chelicerae of female, anterior view; 54, eyes and chelicerae of male, anterior view; 55, male, lateral view; 56, epigynum; 57, 58, spermathecae: 57, left and right spermathecae; 58, left spermatheca; 59, 60, palpus of male: 59, conductor (left, ventral view; right, mesal view); 60, ventral view.

61

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Map 6. Collection localities of Tetragnatha caudata.

Comments. Specimens of T. caudata are distinguished from those of other species in the genus by the extended abdomen. Biology. The usual habitats for T. caudata are bogs, marshes, and swamps where the webs are suspended among reeds and tall grasses.

Tetragnatha vermiformis Emerton Figs. 61–69; Map 7

Tetragnatha vermiformis Emerton, 1885:333, figs. 12–14 (pl. 39); Kaston 1948:272, figs. 877, 878 (pl. 43); Levi 1981:316, figs. 176–184, plate 7i. Male. Total length 4.98 mm; carapace 1.66 mm long, 1.03 mm wide (1 specimen measured). Carapace yellowish. Lateral eyes on each side farther apart than medians on each side (Fig. 63). Legs yellowish. Abdomen silvery on dorsum and sides; sides sometimes with small black spots; venter with silvery spots fewer than on sides. Conductor (Figs. 68, 69) without ridges at base, with tip somewhat expanded, not greatly constricted before tip.

62

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Figs. 61–69. Tetragnatha vermiformis. 61, female, lateral view; 62, eyes and chelicerae of female, anterior view; 63, eyes and chelicerae of male, anterior view; 64, male, lateral view; 65, epigynum; 66, 67, spermathecae: 66, left and right spermathecae; 67, left spermatheca; 68, 69, palpus of male: 68, conductor (left, ventral view; right, mesal view); 69, ventral view. con, conductor; e, embolus; pc, paracymbium; teg, tegulum.

63

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Map 7. Collection localities of Tetragnatha vermiformis.

Female. Total length 8.22, 9.38, 10.38 mm; carapace 2.91, 3.15, 3.49 mm long, 2.24, 2.24, 2.32 mm wide (3 specimens measured). Eyes and coloration as in male (Figs. 61, 62). Epigynum short, broad (Fig. 65); spermathecae small, elongate, slender, parallel, oriented longitudinally (Figs. 66, 67). Range. Washington to Ontario and Massachusetts, south to Nebraska, Florida, and Panama; Asia. Comments. Specimens of T. vermiformis are distinguished from those of other species in the genus by the lack of ridges on the conductor base and by the elongate slender longitudinal spermathecae. Biology. Nothing is recorded.

Tetragnatha pallescens F.O. Pickard-Cambridge Figs. 70–78; Map 8

Tetragnatha pallida Banks, 1892:51, fig. 88.

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Figs. 70–78. Tetragnatha pallescens. 70, female, lateral view; 71, eyes and chelicerae of female, anterior view; 72, eyes and chelicerae of male, anterior view; 73, male, lateral view; 74, epigynum; 75, 76, spermathecae: 75, left and right spermathecae; 76, left spermatheca; 77, 78, palpus of male: 77, conductor (left, ventral view; right, mesal view); 78, ventral view.

65

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Map 8. Collection localities of Tetragnatha pallescens.

Tetragnatha pallescens F.O. Pickard-Cambridge, 1903:436, new name for T. pallida Banks, 1892, preoccupied; Kaston 1948:272, figs. 875, 876 (pl. 43); Levi 1981:308, figs. 129–139, plates 4, 7(a). Eugnatha pallidula Banks, 1910:36, new name for Tetragnatha pallida Banks, 1892 (preoccupied). Male. Total length 7.47 ± 0.80 mm; carapace 2.39 ± 0.21 mm long, 1.42 ± 0.12 mm wide (10 specimens measured). Carapace dark yellow to dark orange. Lateral eyes on each side farther apart than medians on each side (Fig. 72). Legs dark yellow, somewhat darker at tips of segments. Abdomen silvery on dorsum and sides; venter less densely covered with silvery spots than dorsum. Conductor (Figs. 77, 78) with one ridge at base, and with stout curved hook at tip; tip constricted below hook. Female. Total length 9.71 ± 1.52 mm; carapace 2.63 ± 0.36 mm long, 1.75 ± 0.43 mm wide (8 specimens measured). Eyes and coloration as in male (Figs. 70, 71). Epigynum short, rather wide (Fig. 74); spermathecae bulbous, rather large, connected by large lobe (Figs. 75, 76). Range. Washington to Quebec and Massachusetts, south to California, Florida, Panama, and the West Indies. 66

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Comments. Specimens of T. pallescens are distinguished by the strongly hooked conductor tip and by the large lobe connecting the spermathecae on each side. Biology. Habitats recorded for T. pallescens include the foliage of pine trees, as well as tall grass and other herbs near lakes.

Tetragnatha straminea Emerton Figs. 79–87; Map 9

Tetragnatha straminea Emerton, 1885:335, figs. 15, 17, 20, 21 (pl. 39); Kaston 1948:271, figs. 855, 856 (pl. 41), 868–871 (pl. 42); Levi 1981:312, figs. 149–157, plate 4, 7(d). Male. Total length 6.99 ± 0.56 mm; carapace 2.37 ± 0.19 mm long, 1.28 ± 0.11 mm wide (10 specimens measured). Carapace pale orange. Lateral eyes on each side farther apart than medians on each side (Fig. 81). Legs pale orange. Abdomen silvery dorsally; silvery dorsal half abruptly changing to darker ventral half along even line (Fig. 82). Conductor (Figs. 86, 87) with three ridges at base, and with abruptly flared tip; tip with beaklike point.

Map 9. Collection localities of Tetragnatha straminea.

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Figs. 79–87. Tetragnatha straminea. 79, female, lateral view; 80, eyes and chelicerae of female, anterior view; 81, eyes and chelicerae of male, anterior view; 82, male, lateral view; 83, epigynum; 84, 85, spermathecae: 84, left and right spermathecae; 85, left spermatheca; 86, 87, palpus of male: 86, conductor (left, ventral view; right, mesal view); 87, ventral view.

Female. Total length 9.66 ± 1.01 mm; carapace 2.49 ± 0.17 mm long, 1.47 ± 0.10 mm wide (10 specimens measured). Eye spacing and body coloration as in male (Figs. 79, 80). Epigynum short, narrowed posteriorly (Fig. 83); spermathe68

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cae (Figs. 84, 85) somewhat separated, bulbous, one situated anterior to the other and connected to it by slender tube. Range. Northern Alberta to Quebec and Maine, south to Colorado, Texas, Florida, and Cuba. Comments. Specimens of T. straminea are distinguished from those of other species in the genus by the abruptly flared conductor tip and by the spermathecae, one of which is oriented anteriorly, the other posteriorly, and both of which are connected by a slender tube. The color break between dorsal and ventral halves of the abdomen is also useful. Biology. Specimens of T. straminea have been collected in moist habitats such as swamps, bogs, fens, and deep gorges in rocky cliffs.

Tetragnatha shoshone Levi Figs. 88–96; Map 10

Tetragnatha shoshone Levi, 1981:312, figs. 158–166, plate 7(e, f); Uhl et al., 1992:249, figs. 1–39.

Map 10. Collection localities of Tetragnatha shoshone.

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Figs. 88–96. Tetragnatha shoshone. 88, female, lateral view; 89, eyes and chelicerae of female, anterior view; 90, eyes and chelicerae of male, anterior view; 91, male, lateral view; 92, epigynum; 93, 94, spermathecae: 93, left and right spermathecae; 94, left spermatheca; 95, 96, palpus of male: 95, conductor (left, ventral view; right, mesal view); 96, ventral view.

Male. Total length 5.19, 6.80, 7.06 mm; carapace 1.95, 1.99, 2.50 mm long, 1.25, 1.40, 1.41 mm wide (3 specimens measured). Carapace pale orange. Lateral eyes on each side farther apart than medians on each side (Fig. 90). Legs yellow. Abdomen silvery, with pale heart mark and median ventral band. Conductor

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(Figs. 95, 96) with three ridges at base, broad and rounded at tip, lacking point, lacking constriction. Female. Total length 9.40, 10.04, 10.46 mm; carapace 2.60, 2.66, 2.74 mm long, 1.49, 1.70, 1.91 mm wide (3 specimens measured). Eye spacing and body coloration essentially as in male (Figs. 88, 89). Epigynum short, broad, concave on posterior margin (Fig. 92); spermathecae on each side (figs. 93, 94) moderately large, bulbous, touching. Range. Northwest Territories to Ontario, south to northern California, Colorado, and Illinois; Europe. Comments. Specimens of T. shoshone are distinguished from those of other species in the genus by the broad rounded conductor tip and by the longitudinally oriented posterior part of the spermatheca. Biology. Specimens of this species have been collected from tall plants near a lake (Levi 1981). Uhl et al. (1992) also recorded individuals from tall water plants, where the webs trapped adult mosquitoes and midges that emerged from the water.

Tetragnatha extensa (Linnaeus) Figs. 97–105; Map 11

Aranea extensa Linnaeus, 1758:621. Tetragnatha extensa: Latreille 1804:135; Tullgren 1947:130, figs. 1, 2, 7, 8, 16, 17, 19, 20; Locket and Millidge 1953:100, figs. 64a, 64b, 66a, 67a, 69b; Wiehle 1963:12, figs. 5, 10, 13–19; Levi 1981:298, figs. 56–64, plate 5(e); Roberts 1985: 198, figs. 88a, 89a. Tetragnatha manitoba Chamberlin and Ivie, 1942:61, figs. 153–158. Tetragnatha rusticana Chickering, 1959:489, figs. 36–40. Male. Total length 4.87 ± 0.81 mm; carapace 1.96 ± 0.19 mm long, 1.25 ± 0.16 mm wide (10 specimens measured). Carapace orange or dark yellow. Lateral eyes on each side somewhat closer together than medians on each side (Figs. 99, 100). Legs dark yellow. Sternum often dark. Abdomen silvery above; venter with distinct black median longitudinal band; median band flanked by pair of silvery bands. Conductor with tip thick, constricted at base, and produced as short curved hook (Figs. 104, 105). Female. Total length 7.54 ± 0.99 mm; carapace 2.33 ± 0.23 mm long, 1.57 ± 0.13 mm wide (10 specimens measured). Eye spacing and body coloration as in male (Figs. 97, 98). Epigynum short, narrowed and concave posteriorly (Fig. 101); spermathecae (Figs. 102, 103) with anterior part bulbous, extending anteriorly and with posterior part elongate, somewhat curved, extended laterally.

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Figs. 97–105. Tetragnatha extensa. 97, female, lateral view; 98, eyes and chelicerae of female, anterior view; 99, eyes and chelicerae of male, anterior view; 100, male, lateral view; 101, epigynum; 102, 103, spermathecae: 102, left and right spermathecae; 103, left spermatheca; 104, 105, palpus of male: 104, conductor (left, ventral view; right, mesal view); 105, ventral view.

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Map 11. Collection localities of Tetragnatha extensa.

Range. Alaska to insular Newfoundland and Labrador, south to Washington, Colorado and Pennsylvania; Greenland; Europe, Asia. Comments. Specimens of T. extensa are distinguished from those of other species in the genus by the minute curved tip of the conductor and by the elongated, curved, laterally oriented posterior part of the spermatheca. Biology. Specimens of this widespread species have been collected from shrubs and trees in meadows. They occur up to the tree line in Colorado (Levi 1981). In Europe Wiehle (1963) and Neet (1987) noted individuals in great abundance in shore vegetation. Adults are found from late May to early July, and overwintering takes place in early instars. The egg sacs are globular, with one side flattened against a plant stem; the outer silk covering is gray and tufted. West and Toft (1989) described the sexual behavior of T. extensa.

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Tetragnatha laboriosa Hentz Silver Longjawed Orbweaver Figs. 106–114; Map 12

Tetragnatha laboriosa Hentz, 1850:27, fig. 3 (pl. 4); Kaston 1948:269, figs. 850, 851 (pl. 41), 859–861 (pl. 42); Levi 1981:308, figs. 16–22, 120–128, plate 6(h, i). Tetragnatha illinoiensis Keyserling, 1880: 318, fig. 18 (pl. 4). Tetragnatha numa Levi and Levi 1955:37, figs. 19–23. Male. Total length 4.72 ± 0.79 mm; carapace 1.92 ± 0.29 mm long, 1.17 ± 0.17 mm wide (10 specimens measured). Carapace dark yellow or pale orange, sometimes with indistinct dark bands radiating anteriorly from dorsal groove. Lateral eyes on each side usually as far apart as medians on each side, sometimes somewhat closer together or minutely farther apart (Figs. 108, 109). Legs yellow. Abdomen silvery above and on sides; venter with indistinct dark median longitudinal band, which is flanked by pair of silvery bands. Conductor (Figs. 113, 114) with two high thin ridges at base, and with abruptly expanded tip; tip with straight beaklike point.

Map 12. Collection localities of Tetragnatha laboriosa.

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Figs. 106–114. Tetragnatha laboriosa. 106, female, lateral view; 107, eyes and chelicerae of female, anterior view; 108, eyes and chelicerae of male, anterior view; 109, male, lateral view; 110, epigynum; 111, 112, spermathecae: 111, left and right spermathecae; 112, left spermatheca; 113, 114, palpus of male: 113, conductor (left, ventral view; right, mesal view); 114, ventral view.

Female. Total length 6.17 ± 0.43 mm; carapace 1.99 ± 0.18 mm long, 1.25 ± 0.14 mm wide (10 specimens measured). Eye spacing and body coloration as in male (Figs. 106, 107). Epigynum short, broad, concave on posterior margin (Fig. 110); spermathecae (Figs. 111, 112) small, with anterior and posterior parts connected by coiled pouch. 75

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Range. Alaska to Newfoundland, south to California, Florida, and Panama. Comments. Specimens of T. laboriosa are distinguished from those of other species in the genus by the beaklike conductor tip and by the pouchlike connection between anterior and posterior parts of the spermathecae. Biology. Specimens of T. laboriosa are often found in great numbers in fields, roadsides, and crops, even some distance from water, but are also found in bogs, meadows, and marshes. Levi (1981) reports collections from alpine meadows up to 3000 m in Colorado.

Tetragnatha versicolor Walckenaer Figs. 115–123; Map 13

Tetragnatha versicolor Walckenaer, 1841:215; Kaston 1948:270, figs. 852 (pl. 41), 862–864 (pl. 42); Levi 1981:302, figs. 90–109, plates 3, 6(a–f ). Tetragnatha convexa Banks, 1898:247.

Map 13. Collection localities of Tetragnatha versicolor.

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Figs. 115–123. Tetragnatha versicolor. 115, female, lateral view; 116, eyes and chelicerae of male, anterior view; 117, eyes and chelicerae of female, anterior view; 118, male, lateral view; 119, epigynum; 120, 121, spermathecae: 120, left and right spermathecae; 121, left spermatheca; 122, 123, palpus of male: 122, conductor (left, ventral view; right, mesal view); 123, ventral view.

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Tetragnatha limnocharis Seeley, 1928:129, figs. 32–35. Tetragnatha munda Chamberlin and Gertsch, 1929:103, figs. 41–45 (pl. 4). Tetragnatha mariana Archer, 1940:20, fig. 1 (pl. 1). Male. Total length 5.36 ± 0.75 mm; carapace 2.11 ± 0.20 mm long, 1.28 ± 0.13 mm wide (10 specimens measured). Carapace dark yellow or pale orange, sometimes with indistinct markings radiating from dorsal groove. Lateral eyes on each side closer together than medians on each side (Figs. 116, 118), rarely as far apart as medians. Legs yellow or pale orange. Abdomen often silvery dorsally and along sides, with dark pattern dorsally; dark areas of dorsum scalloped at lateral margins (Fig. 118), venter with broad longitudinal band devoid of silvery spots. Conductor (Figs. 122, 123) with three high ridges at base, and with thick rounded tip; tip with minute point. Female. Total length 7.37 ± 1.16 mm; carapace 2.31 ± 0.28 mm long, 1.55 ± 0.20 mm wide (10 specimens measured). Spacing of eyes and coloration of body as in male (Figs. 115, 117). Epigynum short, broad, somewhat concave on posterior margin (Fig. 119); spermathecae (Figs. 120, 121) rather large, bulbous, touching; anterior part extending anteriorly, and posterior part extending essentially posteriorly. Range. Alaska to Newfoundland, south to Baja California, Nicaragua, and Cuba. Comments. Specimens of T. versicolor are distinguished from those of other species in the genus by the thick rounded tip of the conductor, which has a minute point near its base, and by the combination of lateral eyes closer together than the medians and spermathecal parts bulbous, touching, and oriented anteroposteriorly. Biology. The common habitats for individuals of T. versicolor are trees and shrubs near water, though some have been collected in mixed conifer forests or upland aspen stands.

Tetragnatha viridis Walckenaer Figs. 124–133; Map 14

Tetragnatha viridis Walckenaer, 1841:216; Kaston 1948:272; Levi 1981:304, figs. 110–119, plates 3, 6(g). Tetragnatha pinicola Emerton, 1915:139, figs. 7a, 7b. Name preoccupied in genus Tetragnatha. Tetragnatha pinea Seeley, 1928:133, figs. 21–24. New name for T. pinicola Emerton, 1915 (preoccupied). Male. Total length 5.06, 5.73 mm; carapace 1.58, 2.08 mm long, 1.20, 1.45 mm wide (2 specimens measured). Carapace in life green, often with red mark-

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Figs. 124–133. Tetragnatha viridis. 124, female, lateral view; 125, eyes and chelicerae of female, anterior view; 126, eyes and chelicerae of male, anterior view; 127, male, lateral view; 128, epigynum; 129, 130, spermathecae: 129, left and right spermathecae; 130, left spermatheca; 131, patella and tibia I, lateral view; 132, 133, palpus of male: 132, conductor (left, ventral view; right, mesal view); 133, ventral view.

ings, fading to dull yellow in preservative. Lateral eyes on each side approximately as far apart as medians on each side (Figs. 126, 127). Legs green in life, sometimes with red spots at bases of macrosetae, dull yellow in preservative, with

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Map 14. Collection localities of Tetragnatha viridis.

long macrosetae (Fig. 131). Abdomen green in life, sometimes with red markings, silvery in preservative; dorsum with dark area, which is usually straight at sides. Conductor (Figs. 132, 133) with three high ridges at base, and with thickened tip; tip with minute point near base. Female. Total length 5.13, 5.98, 7.14 mm; carapace 1.91, 2.16, 2.24 mm long, 1.33, 1.58, 1.66 mm wide (3 specimens measured). Lateral eyes on each side approximately as far apart as medians on each side (Figs. 124, 125). Body and leg coloration as in male. Epigynum short, broad, somewhat concave along posterior margin (Fig. 128); spermathecae (Figs. 129, 130) rather large, bulbous, touching; anterior part extending anteriorly, and posterior part posterolaterally. Range. Ontario to Nova Scotia, south to eastern Texas and northern Florida. Comments. Living, freshly collected specimens of T. viridis can be distinguished from other species in the genus by the green, or green and red, body and legs. Faded specimens are distinguished from those of T. versicolor, which they closely resemble, by the long macrosetae on the leg tibiae and by the widely separated anterior and posterior lateral eyes. 80

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Biology. Nearly all available specimens of this species were collected on pines, a few on balsam fir. Adults were found during June and early July, only juveniles in other months.

Tetragnatha guatemalensis O. Pickard-Cambridge Figs. 134–143; Map 15

Tetragnatha guatemalensis O. Pickard-Cambridge, 1889:8, figs. 6, 7 (pl. 2); Levi 1981:296, figs. 46–55, plate 5(d). Tetragnatha banksi McCook, 1894:262, figs. 4 (pl. 28), 6 (pl. 25). Tetragnatha intermedia Banks, 1898:247, fig. 14 (pl. 15). Tetragnatha seneca Seeley, 1928:134:, figs. 44–48 (pl. 4); Kaston 1948:271, fig. 872. Tetragnatha laudativa Gertsch and Mulaik, 1936:15, fig. 33. Male. Total length 5.38 ± 0.69 mm; carapace 2.01 ± 0.16 mm long, 1.38 ± 0.09 mm wide (10 specimens measured). Carapace dark orange, sometimes with black markings. Lateral eyes on each side closer together than medians on each side (Figs. 136, 137). Legs dark yellow, sometimes darker. Abdomen silvery, often with dark dorsal pattern; dorsal area with scalloped edges; venter pale.

Map 15. Collection localities of Tetragnatha guatemalensis.

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Figs. 134–143. Tetragnatha guatemalensis. 134, female, lateral view; 135, eyes and chelicerae of female, anterior view; 136, eyes and chelicerae of male, anterior view; 137, male, lateral view; 138, epigynum; 139, 140, spermathecae: 139, left and right spermathecae; 140, left spermatheca; 141–143, palpus of male: 141, conductor (left, ventral view; right, mesal view); 142, ventral view; 143, retrolateral view.

Conductor (Figs. 141, 142) with two low ridges at base, and with slender curved tip; paracymbium with tip angled laterally (Fig. 143). Female. Total length 7.07 ± 1.59 mm; carapace 2.19 ± 0.33 mm long, 1.54 ± 0.20 mm wide (10 specimens measured). Eye spacing and body coloration as in male (Figs. 134, 135). Epigynum approximately as long as broad, somewhat con82

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cave along posterior margin (Fig. 138); spermathecae (Figs. 139, 140) short, plump, extending anteriorly parallel to the main body axis, one somewhat shorter than the other. Range. Wisconsin to Nova Scotia, south to Baja California, Florida, Panama, and the West Indies. Comments. Specimens of T. guatemalensis are distinguished from those of other species of Tetragnatha by the angled tip of the paracymbium and by the short plump spermathecae, both oriented anteriorly and one somewhat shorter than the other. Biology. The common habitat is streamside or lakeside shrubs and tall herbs.

Tetragnatha elongata Walckenaer Figs. 144–156; Map 16

Tetragnatha elongata Walckenaer, 1805:69; Kaston 1948:270, figs. 853, 854 (pl. 41), 865–867 (pl. 42); Levi 1981:300, figs. 74–89, plate 5(g–i). Tetragnatha grallator Hentz, 1850:26, figs. 1, 2 (pl. 4).

Map 16. Collection localities of Tetragnatha elongata.

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Figs. 144–156. Tetragnatha elongata. 144, female, lateral view; 145, eyes and chelicerae of female, anterior view; 146, eyes and chelicerae of male, anterior view; 147, male, lateral view; 148, epigynum; 149, 150, spermathecae: 149, left and right spermathecae; 150, left spermatheca; 151, left chelicera of two females, anterior views; 152, cephalothorax and chelicera of same two females as in 151, lateral views; 153–156, palpus of male: 153–155, conductor: 153, 154, ventral views; 155 (left, ventral view; right, mesal view); 156, ventral view. tib, tibia.

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Male. Total length 6.38 ± 0.89 mm; carapace 2.40 ± 0.23 mm long, 1.51 ± 0.17 mm wide (10 specimens measured). Carapace dark orange with indistinct darker bands radiating from dorsal groove. Lateral eyes on each side closer together than medians on each side (Figs. 146, 147). Chelicerae usually longer than carapace (Fig. 147). Legs dark yellow. Abdomen silvery, with darker pattern on dorsum; dorsal pattern uneven at side margins. Conductor (Figs. 153–156) with two or three ridges and with a transparent flange at base, and with slender tapered tip; tip with minute hook. Female. Total length 8.38 ± 1.23 mm; carapace 2.52 ± 0.33 mm long, 1.63 ± 0.21 mm wide (10 specimens measured). Eye spacing and body coloration as in male (Figs. 144, 145). Abdomen often thick anteriorly and tapered behind (Fig. 144). Epigynum approximately as broad as long, narrowed and concave posteriorly (Fig. 148); spermathecae (Figs. 149, 150) elongate; mesal part thick, longer than lateral part, extending anteriorly, and lateral part short, rather slender, extending anterolaterally or laterally. Range. Southern British Columbia to Newfoundland, south to Baja California, Florida, Mexico, and the West Indies. Comments. Specimens of T. elongata are distinguished from those of other species in the genus by the conductor, which has a transparent flange on its base and a slender evenly tapered tip, and by the spermathecae, the mesal part of which is long and stout and the lateral part short, slender, and extending anterolaterally or laterally. Biology. Individuals of T. elongata usually construct their webs among branches that overhang streams in shady woods (Kaston 1948). The spiders appear to require accessibility to open water if they are not to suffer dehydration (Gillespie 1987). The web has 4 or 5 turns in the attachment zone, a distinct free zone, and 30 to 40 sticky spirals (Levi 1981).

Tetragnatha dearmata Thorell Figs. 157–165; Map 17

Tetragnatha dearmata Thorell, 1873:462; Tullgren 1947:139, figs. 32–44; Wiehle 1963:41, figs. 65–74; Levi 1981:300, figs. 65–73, plate 5(f). Tetragnatha harrodi Levi, 1951:17, figs. 32–37. Male. Total length 6.50 ± 0.75 mm; carapace 2.53 ± 0.26 mm long, 1.60 ± 0.17 mm wide (10 specimens measured). Carapace orange. Lateral eyes on each side distinctly closer together than medians on each side (Figs. 159, 160). Chelicerae shorter than carapace (Fig. 160). Legs dark yellow to pale orange. Abdomen silvery, with dark pattern on dorsum; dark pattern with wavy lateral 85

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Figs. 157–165. Tetragnatha dearmata. 157, female, lateral view; 158, eyes and chelicerae of female, anterior view; 159, eyes and chelicerae of male, anterior view; 160, male, lateral view; 161, epigynum; 162, 163, spermathecae: 162, left and right spermathecae; 163, left spermatheca (two specimens); 164, 165, palpus of male: 164, conductor (left, ventral view; right, mesal view); 165, ventral view.

margins. Conductor (Figs. 159, 160) with two or three ridges at base, and with slender angled tip, lacking transparent flange at base. Female. Total length 8.31 ± 1.23 mm; carapace 2.57 ± 0.34 mm long, 1.67 ± 0.21 mm wide (10 specimens measured). Eye spacing, cheliceral length, and body coloration as in male (Figs. 157, 158). Epigynum somewhat broader than

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Map 17. Collection localities of Tetragnatha dearmata.

long, somewhat concave on posterior margin (Fig. 161); spermathecae (Figs. 162, 163) with mesal part bulbous and lateral part elongate, slender, and extending posterolaterally or posteriorly. Range. Western Northwest Territories to Prince Edward Island, south to Idaho, Oklahoma, and northern New York; northern Europe, northern Asia. Comments. Specimens of T. dearmata are distinguished from those of other Tetragnatha spp. by the slender angled tip on the conductor and by the spermathecae, of which the mesal part is bulbous and the lateral part slender and extended posterolaterally or posteriorly. Biology. Specimens of this species are found both in trees and understorey shrubs in coniferous and aspen forests, and in swamp grasses. Wiehle (1963) gives the maturity time in Europe as June, and, after P. Lehtinen, cites juniper as a common web site in Finland.

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Genus Pachygnatha Sundevall Members of the genus Pachygnatha are small to medium-sized tetragnathids living in leaf litter, under stones and logs, or deep among the grass roots in fields. Juveniles build small horizontal orb webs a few centimetres above the soil surface, where they are suspended from plant stems (Martin 1978), but the ability to build webs is lost in adults, which take prey by searching over the ground. Kovoor (1990) demonstrated the absence of aggregate and flagelliform glands in adults, both types of gland, however, being well developed in the young. Mature males and females are approximately equal in size. Most specimens are caught in pitfall traps. Description. Total length 2.9–6.6 mm. Carapace glabrous, yellowish brown with gray markings, sometimes pitted, rather low, widest at midlength and gently narrowed anteriorly and posteriorly (Figs. 166, 175,185, 195, 205, 215, 225). Eyes usually small, usually subequal but posterior median eyes sometimes distinctly larger than the others and situated on tubercles; posterior row of eyes straight or nearly so; lateral eyes on each side touching. Chelicerae long, stout, diverging; promargin of fang furrow with 3 teeth, and retromargin with 1, 3, or 4 (usually 4) teeth; male chelicera sometimes with anterior spur (Fig. 169). Legs slender, pale, lacking strong macrosetae, with cluster of dorsal trichobothria at base of femora; male sexual modifications lacking. Sternum extended around leg bases. Abdomen broadly elliptical, with grayish pattern on silvery background dorsally; venter usually with indistinct dark markings. Palpus of male (Figs. 172, 182, 192, 202, 212, 222, 232) with rounded bulging tegulum; embolus and conductor long, slender, extending together distally to tip of cymbium; median apophysis absent; paracymbium undivided, long, slender, somewhat angular at sides, movably attached to cymbium (Figs. 172, 173). Epigynum swollen mesally, with short transverse slit, lacking sclerotization (Figs. 167, 176, 186, 196, 206, 216, 226); slit often situated at one-third to one-half the distance from book-lung openings to spinnerets; spermathecae small, usually dark, well separated, round, elliptical, or irregular in outline, connected by softer, often voluminous sac (Figs. 170, 171, 180, 181, 190, 191, 210, 211, 220, 221, 230, 231). Comments. Specimens of Pachygnatha spp. are distinguished from those of other tetragnathid genera by the extension of the sternum around the leg bases, and additionally from those of the similar Glenognatha spp. by having the tracheal spiracle situated in its usual posterior position rather than farther anteriorly. The genus Pachygnatha comprises a world fauna of approximately 20 species, eight of which occur in North America (Levi 1980). Seven are represented in the Canadian fauna, one of which is common to Europe.

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Key to species of Pachygnatha 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2(1).

Chelicerae with spur near base of fang (Figs. 169, 178) . . . . . . . . . . . 3

2'.

Chelicerae without spur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3(2).

Embolus and conductor extending distally two to three times length of tegulum (Fig. 172) . . . . . . . . . . . . . . . xanthostoma C.L. Koch (p. 92)

3'.

Embolus and conductor extending distally at most 1.5 times length of tegulum (Fig. 182) . . . . . . . . . . . . . . . . . . . . clerckii Sundevall (p. 94)

4(2').

Paracymbium extending far distally beyond tegulum (Figs. 192, 193). Posterior median eyes much larger than other eyes (Fig. 188) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . autumnalis Keyserling (p. 96)

4'.

Paracymbium extending little if at all beyond tegulum. Posterior median eyes little if at all larger than other eyes. . . . . . . . . . . . . . . . . . . . . 5

5(4').

Embolus and conductor straight, much longer than tegulum (Fig. 202) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . tristriata C.L. Koch (p. 98)

5'.

Embolus and conductor twisted together, little if at all longer than tegulum (Figs. 212, 222, 232) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

6(5').

Embolus slender at base (Fig. 214). Paracymbium tip pointed, directed distally (Fig. 213). Carapace with conspicuous prominence posterior to each posterior lateral eye (Fig. 208). . . . furcillata Keyserling (p. 100)

6'.

Embolus broad at base (Figs. 222, 224). Paracymbium tip swollen, directed ventrally (Figs. 223, 233). Carapace with less conspicuous prominence posterior to each posterior lateral eye . . . . . . . . . . . . . . . 7

7(6')

Base of embolus nearly as broad as long (Fig. 224) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . brevis Keyserling (p. 102)

7'.

Base of embolus much narrower than long (Fig. 234). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . dorothea McCook (p. 105)

8(1').

Chelicerae with 3 teeth on retromargin of fang furrow. Posterior median eyes distinctly larger than other eyes (Fig. 187) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . autumnalis Keyserling (p. 96)

8'.

Chelicerae with 4 teeth on retromargin of fang furrow. Posterior median eyes little if at all larger than other eyes . . . . . . . . . . . . . . . . . . . . . . . 9

9(8').

Epigynum with small angular sclerite (Fig. 196) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . tristriata C.L. Koch (p. 98)

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9'.

Epigynum without sclerite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

10(9').

Carapace with conspicuous prominence posterior to each posterior lateral eye (Fig. 207) . . . . . . . . . . . . . . . . furcillata Keyserling (p. 100)

10'.

Carapace with less conspicuous prominence posterior to each posterior median eye . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

11(10'). Carapace length less than 2.0 mm . . . . xanthostoma C.L. Koch (p. 92) 11'.

Carapace length more than 2.0 mm . . . . . . . . . . . . . . . . . . . . . . . . . 12

12(11'). Sac connecting spermathecae large, with large dorsal prominence (Figs. 180, 181) . . . . . . . . . . . . . . . . . . . . . . clerckii Sundevall (p. 94) 12'.

Sac connecting spermathecae smaller, with small dorsal prominence or no prominence (Figs. 220, 221, 230, 231). . . . . . . . . . . . . . . . . . . . . 13

13(12'). Spermathecae arising far anteriorly on connecting sac (Figs. 220, 221) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . brevis Keyserling (p. 102) 13'.

Spermathecae arising less far anteriorly on connecting sac (Figs. 230, 231) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . dorothea McCook (p. 105)

Clé des espèces de Pachygnatha 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2(1).

Chélicères munis d'un éperon près de la base du crochet (figs. 169, 178) .....................................................3

2'.

Chélicères sans éperon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3(2).

Longueur de la projection formée par l'embolus et le conducteur de deux à trois fois plus grande que celle du tégulum (fig. 172) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xanthostoma C.L. Koch (p. 92)

3'.

Longueur de la projection formée par l'embolus et le conducteur au plus 1.5 fois celle du tégulum (fig. 182) . . . . . . . . clerckii Sundevall (p. 94)

4(2').

Paracymbium se prolongeant bien au-delà du tégulum (figs. 192, 193). Yeux postérieurs médians beaucoup plus gros que les autres yeux (fig. 188) . . . . . . . . . . . . . . . . . . . . . . . autumnalis Keyserling (p. 96)

4'.

Paracymbium ne se prolongeant pas au-delà du tégulum, ou à peine. Yeux postérieurs médians à peine plus gros que les autres yeux . . . . . 5

5(4').

Embolus et conducteur droits et beaucoup plus long que le tégulum (fig. 202) . . . . . . . . . . . . . . . . . . . . . . . . . tristriata C.L. Koch (p. 98)

90

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5'.

Embolus et conducteur vrillés et à peine plus long que le tégulum (figs. 212, 222, 232) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

6(5').

Base de l'embolus étroite (fig. 214). Apex du paracymbium en pointe et dirigé vers l'avant (fig. 213). Céphalothorax muni de protubérances saillantes derrière chaque œil latéral postérieur (fig. 208) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . furcillata Keyserling (p. 100)

6'.

Base de l'embolus large (figs. 222, 224). Apex du paracymbium arrondi et pointant ventralement (figs. 223, 233). Céphalothorax muni de protubérances moins saillantes derrière chaque œil latéral postérieur . . . . 7

7(6')

Base de l'embolus presque aussi large que longue (fig. 224) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . brevis Keyserling (p. 102)

7'.

Base de l'embolus beaucoup plus mince que longue (fig. 234) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . dorothea McCook (p. 105)

8(1').

Chélicères armés de 3 dents sur la marge antérieure de la gouttière du crochet. Yeux médians postérieurs beaucoup plus gros que les autres yeux (fig. 187) . . . . . . . . . . . . . . . . . . . autumnalis Keyserling (p. 96)

8'.

Chélicères armés de dents sur la marge antérieure de la gouttière du crochet. Yeux médians postérieurs à peine plus gros que les autres yeux . 9

9(8').

Épigyne muni d'un petit sclérite formant un angle (fig. 196) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . tristriata C.L. Koch (p. 98)

9'.

Épigyne sans sclérite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

10(9').

Céphalothorax muni de protubérances saillantes derrière chaque œil latéral postérieur (fig. 207) . . . . . . . . . . . furcillata Keyserling (p. 100)

10'.

Céphalothorax muni protubérances moins saillantes derrière chaque œil latéral postérieur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

11(10'). Céphalothorax de moins de 2.0 mm. . . xanthostoma C.L. Koch (p. 92) 11'.

Céphalothorax de plus de 2.0 mm . . . . . . . . . . . . . . . . . . . . . . . . . . 12

12(11'). Structure reliant les spermathèques formant une grande poche dont la partie dorsale en très developpée (figs. 180, 181) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . clerckii Sundevall (p. 94) 12'.

Structure reliant les spermathèques formant une petite poche dont la partie dorsale est peu développée ou inexistante (figs. 220, 221, 230, 231) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

13(12'). Spermathèques insérées dans la partie antérieure de l’épigyne (figs. 220, 221) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . brevis Keyserling (p. 102) 13'.

Spermathèques insérées près du milieu de l’épigyne (figs. 230, 231) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . dorothea McCook (p. 105) 91

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Pachygnatha xanthostoma C.L. Koch Figs. 166–174; Map 18

Pachygnatha xanthostoma C.L. Koch, 1845f:148, figs. 1068, 1069 (pl. 431); Levi 1980:58, figs. 160, 161, 214–225. Male. Total length 2.96 ± 0.18 mm; carapace 1.47 ± 0.08 mm long, 1.07 ± 0.04 mm wide (10 specimens measured). Carapace yellowish brown, with gray markings. Eyes approximately equal in size. Chelicerae with spur near base of

Figs. 166–174. Pachygnatha xanthostoma. 166, female, dorsal view; 167, abdomen of female, ventral view; 168, eyes and chelicerae of female, anterior view; 169, eyes and chelicerae of male, anterior view; 170, 171, spermathecae: 170, dorsal view; 171, lateral view; 172–174, palpus of male: 172, ventral view; 173, retrolateral view; 174, embolus and conductor. con, conductor; e, embolus; pc, paracymbium; teg, tegulum.

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Map 18. Collection localities of Pachygnatha xanthostoma.

fang (Fig. 169). Legs yellowish. Abdomen dark, with indistinct black pattern; venter with broad dark median band (as in Fig. 167). Palpus (Figs. 172–174) with embolus and conductor twisted together, extending distally two to three times length of tegulum; paracymbium long, blunt at tip (Fig. 173). Female. Total length 3.76 ± 0.37 mm; carapace 1.65 ± 0.11 mm long, 1.20 ± 0.12 mm wide (10 specimens measured). Coloration as in male (Figs. 166, 167). Chelicerae lacking spurs (Fig. 168). Epigynum situated about one-third distance from book lungs to spinnerets (Fig. 167); spermathecae large, elliptical (ventral view, Fig. 170), connected by triangular sac (Figs. 170, 171). Range. Alberta and eastern Washington to eastern New Brunswick, south to Utah, Colorado, and Pennsylvania. Comments. Specimens of P. xanthostoma are distinguished from those of other species in the genus by their small size, by the great length of the embolus and conductor, by the large elliptical spermathecae, and by the angular sac connecting the spermathecae. Biology. Collections of P. xanthostoma have been made in pitfall traps, plant litter, or under logs and boards on the ground. Kaston (1948) indicates that individuals overwinter both as adults and subadults. 93

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Pachygnatha clerckii Sundevall Figs. 175–184; Map 19

Pachygnatha clerckii Sundevall, 1823:16; Locket and Millidge 1953:106, figs. 71, 72, 73A, 73D; Wiehle 1963:61, figs. 99–106; Levi 1980:59, figs. 226–237; Roberts 1985: 199, figs. 88g, 89g. Pachygnatha sewardi Chamberlin and Ivie, 1947:64, figs. 76–78.

Figs. 175–184. Pachygnatha clerckii. 175, female, dorsal view; 176, abdomen of female, ventral view; 177, eyes and chelicerae of female, anterior view; 178, eyes and chelicerae of male, anterior view; 179, left chelicera of male, posterior view; 180, 181, spermathecae: 180, dorsal view; 181, lateral view; 182–184, palpus of male: 182, ventral view; 183, retrolateral view; 184, embolus and conductor.

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Map 19. Collection localities of Pachygnatha clerckii.

Male. Total length 4.97 (4.48–5.93) mm; carapace 2.38 (2.08–2.66) mm long, 1.80 (1.74–1.91) mm wide (7 specimens measured). Carapace yellowish, with indistinct dark streaks at midline and radiating from dorsal groove (Fig. 175). Chelicerae with spur near base of fang (Fig. 178). Legs yellowish. Abdomen with slender median longitudinal dark band and with two broader darker bands laterally (Fig. 175); venter with interrupted grayish median band (as in Fig. 176). Palpus with embolus and conductor twisted together, extending distally a distance approximately equal to length of tegulum (Figs. 182–184); paracymbium short, rounded at tip, with short straight process on dorsal margin (Fig. 183). Female. Total length 5.62 ± 0.41 mm; carapace 2.48 ± 0.17 mm long, 1.90 ± 0.17 mm wide (10 specimens measured). Coloration as in male (Figs. 175, 176). Chelicerae lacking spur near base of fang (Fig. 177). Epigynum situated approximately one-fourth distance from book-lung openings to spinnerets (Fig. 176); spermathecae small, elliptical, dark, connected by large rounded sac (Figs. 180, 181). Range. Alaska and interior British Columbia, east to Ontario and Virginia; Europe, Asia. Comments. Specimens of P. clerckii are distinguished from those of other species in the genus by the short paracymbium having a rounded tip and a short

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straight process on its dorsal margin, and by the large rounded sac connecting the spermathecae. Biology. Specimens of P. clerckii have been collected in moist areas such as swamps and flood plains, and at the margins of ponds and peat bogs (Wiehle 1963). The egg sacs are attached to bark, stones, or moss, and are guarded by the female. There is one generation each year, with mating and oviposition in spring; adults appear in autumn, winter, and spring (Alderweireldt and De Keer 1990).

Pachygnatha autumnalis Keyserling Figs. 185–194; Map 20

Pachygnatha autumnalis Keyserling, 1884:660, figs. 10, 10a, 10b (pl. 21); Kaston 1948:266, figs. 840 (pl. 40), 849 (pl. 41); Levi 1980:58, plate 7, figs. 155, 158, 159, 202–213. Male. Total length 4.05 ± 0.30 mm; carapace 2.07 ± 0.12 mm long, 1.39 ± 0.07 mm wide (10 specimens measured). Carapace dark brown, paler posterolat-

Map 20. Collection localities of Pachygnatha autumnalis.

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Figs. 185–194. Pachygnatha autumnalis. 185, female, dorsal view; 186, abdomen of female, ventral view; 187, eyes and chelicerae of female, anterior view; 188, eyes and chelicerae of male, anterior view; 189, left chelicera of male, posterior view; 190, 191, spermathecae: 190, dorsal view; 191, lateral view; 192–194, palpus of male: 192, ventral view; 193, retrolateral view; 194, embolus and conductor. pc, paracymbium.

erally and at side margins. Chelicerae strongly divergent, lacking spurs (Figs. 188, 189). Posterior median eyes enlarged, set on a large tubercle (Fig. 188), with pair of broken longitudinal bands near midline and pair of wavy black longitudinal bands laterally (as in Figs. 185, 190); venter with indistinct dark median band (as in Fig 186). Palpus with embolus and conductor twisted together, approximately as long as tegulum (Figs. 192–194); paracymbium long, slender, pointed distally, with small hook on dorsal margin (Fig. 193). 97

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Female. Total length 5.40 ± 0.47 mm; carapace 2.30 ± 0.13 mm long, 1.58 ± 0.13 mm wide (10 specimens measured). Coloration as in male (Figs. 185, 186). Chelicerae less divergent than in male, and with 3 teeth on posterior margin of fang furrow. Posterior median eyes enlarged, set on a large tubercle (Fig. 187). Epigynum situated approximately two-fifths the distance between book-lungs and spinnerets (Fig. 186); spermathecae hooked at tips (Figs. 190, 191). Range. Southern Ontario to Massachusetts, south to Arkansas, Florida, and Cuba. Comments. Specimens of P. autumnalis are distinguished from those of other species in the genus by the large posterior median eyes, which are set on a tubercle, the long slender pointed paracymbium, and by the hooked spermathecae. Biology. Individuals have been collected by the use of pitfall traps in plant debris on the ground and in abandoned fields.

Pachygnatha tristriata C.L. Koch Figs. 195–204; Map 21

Pachygnatha tristriata C.L. Koch, 1845f:145, fig. 1066 (pl. 431); Kaston 1948:266, figs. 838, 839 (pl. 40), 847, 848 (pl. 51); Levi 1980:60, plate 7, figs. 238–250.

Map 21. Collection localities of Pachygnatha tristriata.

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Figs. 195–204. Pachygnatha tristriata. 195, female, dorsal view; 196, abdomen of female, ventral view; 197, eyes and chelicerae of female, anterior view; 198, eyes and chelicerae of male, anterior view; 199, left chelicera of male, posterior view; 200, 201, spermathecae: 200, dorsal view; 201, lateral view; 202–204, palpus of male: 202, ventral view; 203, retrolateral view; 204, embolus and conductor. scl, sclerite; teg, tegulum.

Male. Total length 5.27 ± 0.44 mm; carapace 2.55 ± 0.23 mm long, 1.79 ± 0.09 mm wide (10 specimens measured). Carapace orange, with dark band at midline, dark side margins, and dark bands diverging anteriorly from dorsal groove. Chelicerae strongly divergent distally, with knobbed tooth on posterior margin of fang furrow (Figs. 198, 199). Legs yellowish or orange. Abdomen with median row of whitish spots, and with paired curved lateral black lines (as in 99

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Fig. 195); venter with broad median dark band, which subdivides posterior to genital opening (as in Fig. 196). Palpus with conductor and embolus straight, much longer than tegulum (Figs. 202, 204); paracymbium extending as far distally as distal margin of tegulum, slender and pointed, with strong hook on dorsal margin (Fig. 203). Female. Total length 5.79 ± 0.66 mm; carapace 2.63 ± 0.28 mm long, 1.81 ± 0.15 mm wide (10 specimens measured). Coloration as in male (as in Figs. 195, 196). Chelicerae moderately divergent (Fig. 197), with four teeth on posterior margin of fang furrow. Epigynum with narrow triangular sclerite (Fig. 196); spermathecae little sclerotized, connected by large angular sac (Figs. 200, 201). Range. Alberta to Nova Scotia, south to eastern Texas and northern Florida. Comments. Specimens of P. tristriata differ from those of other species in the genus by the straight embolus and conductor and by the presence of a single knobbed tooth on the posterior margin of the fang furrow in males, and by the triangular epigynal sclerite and weakly sclerotized spermathecae of females. Biology. Collections are by pitfall trap from meadows and pastures, or they are found under stones, logs, and boards. Adults are present in most months in Connecticut (Kaston 1948).

Pachygnatha furcillata Keyserling Figs. 205–214; Map 22

Pachygnatha furcillata Keyserling, 1884:662, fig. 11 (pl. 21); Kaston 1948:267, figs. 842 (pl. 40), 858 (pl. 52); Levi 1980:53, figs. 154, 156, 157, 162–176. Male. Total length 5.45 ± 0.42 mm; carapace 2.67 ± 0.26 mm long, 1.94 ± 0.25 mm wide (10 specimens measured). Carapace orange posteriorly, yellowish anteriorly, with faint dark median band and with some dark lines radiating from dorsal groove, with pair of low bulges posterior to eyes (Fig. 208). Chelicerae stout, strongly divergent distally, with four minute teeth on posterior margin of fang furrow (one well separated from the others). Legs yellowish orange. Abdomen with broad dark broken median band and angular lateral bands (Fig. 205); venter with broad dark interrupted median band (Fig. 206). Palpus with embolus and conductor moderately long, twisted together (Figs. 212–214); embolus slender; paracymbium short, extending distally only to distal margin of tegulum, with pointed, somewhat thickened tip; tip of paracymbium directed distally (Fig. 213). Female. Total length 5.78 ± 0.48 mm; carapace 2.63 ± 0.17 mm long, 2.09 ± 0.23 mm wide (10 specimens measured). Coloration as in male (Figs. 205, 206).

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Figs. 205–214. Pachygnatha furcillata. 205, female, dorsal view; 206, abdomen of female, ventral view; 207, eyes and chelicerae of female, anterior view; 208, eyes and chelicerae of male, anterior view; 209, left chelicera of male, posterior view; 210, 211, spermathecae: 210, dorsal view; 211, lateral view; 212–214, palpus of male: 212, ventral view; 213, retrolateral view; 214, embolus and conductor. con, conductor; e, embolus; pc, paracymbium.

Chelicerae less divergent than in male (Fig. 207). Epigynum somewhat closer to book lungs than to spinnerets (Fig. 206); spermathecae small, well sclerotized, connected by large angular sac (Figs. 210, 211). Range. Indiana to Massachusetts, south to Florida. Comments. Specimens of P. furcillata are distinguished from those of other species in the genus by the distinct prominence on the carapace posterior to the posterior lateral eye on each side, by the distally directed tip on the paracymbium, and by the large angular sac connecting the spermathecae. The southernmost

101

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Map 22. Collection localities of Pachygnatha furcillata.

specimens are smaller than those in the north, and the females possess a spur of variable length on the anterior surface of each chelicera (Levi 1980). Further study of the southern population seems desirable. Biology. Collections of P. furcillata have been made in moist forests and in bogs and swamps.

Pachygnatha brevis Keyserling Figs. 215–224; Map 23

Pachygnatha tristriata Keyserling, 1883:209. Name preoccupied in genus Pachygnatha. Pachygnatha brevis Keyserling, 1884:658. New name to replace P. tristriata Keyserling, 1883, preoccupied; Kaston 1948:267, figs. 841 (pl. 40), 857 (pl. 52); Levi 1980:54, figs. 178–189. 102

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Figs. 215–224. Pachygnatha brevis. 215, female, dorsal view; 216, abdomen of female, ventral view; 217, eyes and chelicerae of female, anterior view; 218, eyes and chelicerae of male, anterior view; 219, left chelicera of male, posterior view; 220, 221, spermathecae: 220, dorsal view; 221, lateral view; 222–224, palpus of male: 222, ventral view; 223, retrolateral view; 224, embolus and conductor.

Male. Total length 5.54 ± 0.25 mm; carapace 2.65 ± 0.12 mm long, 2.11 ± 0.16 mm wide (10 specimens measured). Carapace yellowish brown, with broad dark median band and with some indistinct dark bands radiating from dorsal groove; median band extending to anterior median eyes (Fig. 215). Chelicerae long, stout, with four teeth on the posterior margin of the fang furrow (Figs. 218, 219). Legs yellowish orange. Abdomen with faintly indicated narrow median band and paired broken lateral bands; venter with broad median band. Palpus with embolus and conductor rather short, twisted together; embolus broad at base (Figs. 222, 224); paracymbium short, with tip swollen and directed ventrally (Fig. 223). 103

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Map 23. Collection localities of Pachygnatha brevis.

Female. Total length 6.04 ± 0.40 mm; carapace 2.57 ± 0.20 mm long, 1.96 ± 0.16 mm wide (10 specimens measured). Coloration as in male (Figs. 215, 216). Chelicerae relatively shorter than in male (Fig. 217). Epigynum usually situated approximately one-third the distance from book lungs to spinnerets (Fig. 216); spermathecae small, elliptical, connected by short rounded sac (Figs. 220, 221). Range. Southern Ontario to Nova Scotia, south to Illinois and Virginia. Comments. Specimens of P. brevis are distinguished from those of other species of Pachygnatha by the broad embolus base and by the short rounded sac connecting the spermathecae. Biology. Collections of P. brevis are from swamps and salt marshes, or from plant debris in water courses or under logs.

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Pachygnatha dorothea McCook Figs. 225–234; Map 24

Pachygnatha dorothea McCook, 1894:27, figs. 3, 4 (pl. 26); Levi 1980:56, figs. 190–201. Pachygnatha kuratai Levi, 1951:15, figs. 29–31.

Figs. 225–234. Pachygnatha dorothea. 225, female, dorsal view; 226, abdomen of female, ventral view; 227, eyes and chelicerae of female, anterior view; 228, eyes and chelicerae of male, anterior view; 229, left chelicera of male, posterior view; 230, 231, spermathecae: 230, dorsal view; 231, lateral view; 232–234, palpus of male: 232, ventral view; 233, retrolateral view; 234, embolus and conductor (left, ventral view; right, dorsal view).

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Map 24. Collection localities of Pachygnatha dorothea.

Male. Total length 4.93 ± 0.47 mm; carapace 2.44 ± 0.14 mm long, 1.88 ± 0.09 mm wide (10 specimens measured). Carapace orange, with dark median band and some dark bands radiating from dorsal groove; median band extending to anterior median eyes. Chelicerae long, stout, strongly divergent (Figs. 228, 229), with four posterior teeth arranged in diads. Legs orange. Abdomen with paired lateral bands reduced to series of irregular spots; venter lacking distinct median band. Palpus with embolus and conductor rather short, twisted together; embolus with base rather broad (Figs. 232, 234); paracymbium rather short, with tip thickened and directed ventrally (Fig. 233). Female. Total length 5.58 ± 0.57 mm; carapace 2.49 ± 0.17 mm long, 1.84 ± 0.11 mm wide (10 specimens measured). Coloration as in male (Figs. 225, 226). Chelicerae somewhat shorter than in male (Fig. 227). Epigynum situated approximately midway between book lungs and spinnerets or somewhat closer to spinnerets (Fig. 226); spermathecae small, elliptical, well separated, connected by large lobed sac (Figs. 230, 231). Range. Vancouver Island to Maine, south to New Mexico and southern New York. Comments. Specimens of P. dorothea are distinguished from those of other species in the genus by the rather broad embolus base and by the lobed sac connecting the spermathecae.

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Biology. Specimens have been collected from plant debris on lake shores and river banks, and in low-growing plants such as skunk cabbage and pitcher plants.

Genus Metellina Chamberlin & Ivie Members of the genus Metellina build their orb webs in many kinds of habitat, some seeming to favor open shrubby fields, forest margins, or gardens, others preferring moister places such as greenhouses, cellars, caves, or poorly illumined thickets near creeks (Wiehle 1931). The web is small to moderately large, and, like that of Meta spp., has an open hub. The web varies in orientation, even within species, from nearly vertical to nearly horizontal. A nearly vertical web may often be eccentric, with as many as 30–50 catching spirals in the lower half and only 14–20 in the upper half. Radial threads number approximately 20. When hunting, the spider often wraps its prey, hangs it in the web, and returns for an interval of time to the hub before feeding. Maturity and mating occur either in spring or in autumn, depending on the species. Description. Total length 3.1–12.0 mm. Carapace rather low, distinctly narrowed anteriorly, yellowish white to light brown, with scattered diffuse dark patches (Fig. 245). Eyes subequal in size; lateral eyes on each side touching; posterior row of eyes approximately straight. Chelicerae stout (Figs. 235, 244); promargin of fang furrow with 3 teeth, retromargin with 3. Legs yellowish white, with dark rings at middle and tip of distal segments; femora lacking long trichobothria; male legs not modified sexually. Abdomen (Fig. 245) ovoid, widest and highest in anterior third, sometimes with small indistinct black spots; venter with broad black longitudinal band, which is bounded laterally by white (Fig. 246). Palpus of male (Figs. 238, 239, 243, 253, 254) with short to moderately long tibia; tegulum large, prominent; conductor and embolus arising laterally on genital bulb and arching mesally then distally to tip of bulb; embolus with broad angular base, with small slender embolar apophysis, and with curved slender tip; paracymbium large, with 1 or 2 teeth, or a fingerlike process, near base of lateral branch (Figs. 238, 239, 243, 253, 254). Epigynum (Figs. 236, 241, 242, 247, 249, 251) small; median septum usually indistinct, sometimes with median depression; spermathecae large, bilobed, well separated (Figs. 237, 240, 248, 250). Comments. Members of the genus Metellina are distinguished from those of other tetragnathid genera by the large paracymbium, by the small slender embolar apophysis, and by the moderately large, bilobed and well-separated spermathecae. Levi (1980) recognized eight world species of Metellina, of which three are Eurasian and two North American. One of the Eurasian species, M. segmentata (Clerck), is apparently introduced in Canada, and two native species are also represented here.

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Key to species of Metellina 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2(1).

Palpal tibia approximately twice as long as wide (Figs. 243, 253, 254). ......................................................

2'.

Palpal tibia hardly longer than wide (Figs. 238, 239) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . mimetoides Chamberlin & Ivie (p. 109)

3(2).

Base of palpal conductor broad, smoothly curved (Fig. 243) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . segmentata (Clerck) (p. 111)

3'.

Base of palpal conductor more slender, somewhat angular (Fig. 253) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . curtisi (McCook) (p. 113)

4(1').

Median septum with distinct lateral margins (Fig. 241) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . segmentata (Clerck) (p. 111)

4'.

Median septum with lateral margins not developed, or hardly visible (Figs. 236, 247, 249, 251) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

5(4').

Epigynum with median depression approximately as wide as long (Figs. 247, 249, 251) . . . . . . . . . . . . . . . . . curtisi (McCook) (p. 113)

5'.

Epigynum with median depression distinctly wider than long (Fig. 236) . . . . . . . . . . . . . . . . . . . . . . . . mimetoides Chamberlin & Ivie (p. 109)

Clé des espèces de Metellina 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2(1).

Tibia du palpe environ deux fois plus long que large (figs. 243, 253, 254) .....................................................3

2'.

Tibia du palpe à peine plus long que large (figs. 238, 239) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . mimetoides Chamberlin & Ivie (p. 109)

3(2).

Base du conducteur élargie et d'une courbure régulière (fig. 243) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . segmentata (Clerck) (p. 111)

3'.

Base du conducteur étroite formant presque un angle droit avec la partie terminale (fig. 253) . . . . . . . . . . . . . . . . . . . curtisi (McCook) (p. 113)

4(1').

Septum médian muni de marges latérales bien marquées (fig. 241) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . segmentata (Clerck) (p. 111)

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4'.

Septum médian sans marges latérales ou à peine visibles (figs. 236, 247, 249, 251) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

5(4').

Dépression du centre de l'épigyne presque aussi large que longue (figs. 247, 249, 251) . . . . . . . . . . . . . . . . . . curtisi (McCook) (p. 113)

5'.

Dépression du centre de l'épigyne beaucoup plus large que longue (fig. 236) . . . . . . . . . . . . . . . . mimetoides Chamberlin & Ivie (p. 109)

Metellina mimetoides Chamberlin & Ivie Figs. 235–239; Map 25

Metellina mimetoides Chamberlin and Ivie, 1941:15, fig. 19 (pl. 2); Levi 1980:36, figs. 87–94. Male. Total length 3.53, 3.80, 4.20 mm; carapace 1.83, 1.90, 2.01 mm long, 1.58, 1.60, 1.66 mm wide (3 specimens measured). Carapace yellowish white or grayish, darker at dorsal groove and anterolaterally. Lateral eyes on each side touching (Fig. 235). Legs yellowish white, with dark rings. Sternum black.

Figs. 235–239. Metellina mimetoides. 235, eyes and chelicerae of male, anterior view; 236, epigynum; 237, spermathecae; 238, 239, palpus of male: 238, ventral view; 239, dorsal view. con, conductor; pc, paracymbium.

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Map 25. Collection localities of Metellina mimetoides.

Abdomen white, with paired dark patches; venter with broad black median band; band bordered with white. Palpal tibia hardly longer than wide (Figs. 238, 239); conductor rather slender, somewhat angular at base (Fig. 238); base of embolus large, angular; paracymbium with peglike tooth near base of lateral branch (Fig. 239). Female. Total length 4.44 (4.07–5.00) mm; carapace 1.57 (1.56–2.08) mm long, 1.47 (1.32–1.74) mm wide (4 specimens measured). Color and structure 110

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essentially as in male, but abdomen with anterolateral humps. Epigynum with median depression wider than long, subdivided at midline (Fig. 236); spermathecae moderately large, bilobed (Fig. 237). Range. Southern Alaska to Baja California, inland to Montana, Oklahoma and Texas. The Great Plains specimens are from caves. Comments. Specimens of M. mimetoides can be distinguished from those of other species in the genus by the short palpal tibia of males, and by the great width of the epigynal median depression of females (ratio of width to length greater than 2.0). Biology. The habitat of M. mimetoides is believed to be open disturbed places such as wood piles or the outer walls of buildings, as well as low shrubs or rock overhangs (Levi 1980). Specimens are sometimes also found in caves.

Metellina segmentata (Clerck) Figs. 240–243; Map 26

Araneus segmentatus Clerck, 1758:45, fig. 6 (pl. 2). Aranea reticulata Linnaeus, 1758:619. Meta reticulata: Wiehle 1931:119, figs. 192–197.

Figs. 240–243. Metellina segmentata. 240, spermathecae; 241, 242, epigynum: 241, ventral view; 242, posterior view; 243, palpus of male, ventral view. con, conductor; e, embolus.

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Map 26. Collection localities of Metellina segmentata.

Metellina segmentata: Levi 1980:36, figs. 99–104. Male. Total length 4.96 ± 0.85 mm; carapace 2.31 ± 0.35 mm long, 1.98 ± 0.27 mm wide (10 specimens measured). Carapace yellowish white, with dark midstripe and pair of dark parallel lines posteriorly, and with paired angular dark marks posterior to lateral eyes. Legs yellowish white, with dark rings. Sternum dark, somewhat paler mesally. Abdomen yellowish or greenish, with minute dark spots forming mesal band, and with fine black midstripe; midstripe giving off paired lateral branches; venter with broad dark mesal band; band bordered with white. Palpus of male (Fig. 243) with tibia approximately twice as long as wide; conductor broad, smoothly curved at base; embolus with large elongated base,

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with small slender embolar apophysis, and with slender curved tip; paracymbium large, its lateral branch with broad tooth near base. Female. Total length 4.81 (3.65–5.81) mm; carapace 2.13 (1.83–2.41) mm long, 1.64 (1.27–2.10) mm wide (5 specimens measured). Coloration as in male, but somewhat paler. Median septum of epigynum with distinct parallel lateral margins (Figs. 241, 242); spermathecae moderately large, bilobed, well separated (Fig. 240). Range. Vancouver area, where a population has apparently been introduced; Europe, Asia. Comments. Specimens of M. segmentata are distinguished from those of other species in the genus by the broad smoothly curved conductor base in males and by the distinct lateral margins of the median septum in females. Bonnet (1957) lists several Old World synonyms of M. segmentata, but these have not been critically examined by modern authors. Biology. Individuals of M. segmentata are basically herb dwellers, building their sloped orb webs in tall grass, low shrubs, forest margins, and gardens, but some also build among tree branches. The web has an open hub, four or five attachment-zone threads, and 17–25 (usually about 20) radials (Wiehle 1931). The spider sits at the hub most of the day, with legs I and II stretched forward and the other pairs to the rear. Occasional individuals sit under a nearby leaf or grass blade, in contact with the hub via a thread. Adults appear at the end of August in Germany and persist until October (Wiehle 1931). Males may congregate at the periphery of a female's web, each bearing a fly which it first catches and trusses with silk thread. Courtship consists of the presentation of the fly to the female; if receptive, she grabs the prey, throws additional silk around it, and feeds while mating. Egg cocoons are suspended from a twig or in bark crevices, usually in the vicinity of the female's web. The sac is globular, and made of a thin layer of white silk. The eggs overwinter, and hatch the following spring. Prenter et al. (1994, 1995) give additional biological data from Britain.

Metellina curtisi (McCook) Figs. 244–254; Map 27

Epeira peckhamii McCook, 1894:189, figs. 5, 6 (pl. 18). Pachygnatha curtisi McCook, 1894:271, fig. 5 (pl. 26). Specific name chosen by first revisor. Metellina curtisi: Chamberlin and Ivie 1941:15, fig. 20; Levi 1980:35, figs. 72–86, 95–98; plate 6. Male. Total length 4.62 ± 0.72 mm; carapace 2.21 ± 0.51 mm long, 1.66 ± 0.30 mm wide (10 specimens measured). Carapace yellowish white, with dark

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Figs. 244–254. Metellina curtisi. 244, eyes and chelicerae of male, anterior view; 245, female, dorsal view; 246, abdomen of female, ventral view; 247, 249, 251, 252, epigynum: 247, 249, 251, ventral views; 252, posterior view; 248, 250, spermathecae; 253, 254, palpus of male: 253, ventral view; 254, dorsal view. con, conductor; pc, paracymbium.

spots. Legs yellowish white, with dark rings. Sternum black. Abdomen whitish, with extensive grayish or black spotting; spots surrounded by whitish areas (Fig. 245). Palpus of male (Figs. 253, 254) with tibia approximately twice as long as wide; conductor rather slender, somewhat angled at base, extending to tip of bulb; embolus with large angular base, small embolar apophysis, and slender tip; paracymbium large; lateral branch of paracymbium with small fingerlike process at base. Female. Total length 4.54 ± 0.79 mm; carapace 1.74 ± 0.21 mm long, 1.44 ± 0.17 mm wide (10 specimens measured). Coloration essentially as in male. 114

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Map 27. Collection localities of Metellina curtisi.

Abdomen sometimes with small paired humps (Fig. 245). Epigynum with median septum having lateral margins indistinct, sometimes with slender median ridge between depressions (Figs. 247, 249, 251); spermathecae moderately large, bilobed, well separated (Figs. 248, 250). Range. Southern Alaska to California, with a few records in the Great Lakes area. Comments. Specimens of M. curtisi are distinguished from those of other Metellina spp. by the small fingerlike process, which is set close to the mesal branch of the paracymbium, in males, and by the indistinct lateral margins of the median septum in females. Biology. Specimens of M. curtisi have been collected among shrubs and in dense coniferous forests on the Pacific coast. A few were caught on buildings. The web has the hub open. Don J. Boe (in Levi 1980) observed webs 10–18 cm in diameter and sloped up to 10° from vertical, one web, however, being horizontal. Nineteen to 25 radii were counted, and 11–19 spirals in the upper half, 15–23 below. Adults appear in early spring and persist until autumn or early winter (Levi 1980). 115

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Genus Meta C.L. Koch Representatives of the genus Meta are dusky inhabitants of cool dark places such as caves, wells, mine shafts, cellars, and moist stone piles in dense forests. The web is vertical or nearly so, and the spider rests at the hub. Egg sacs are suspended on a thread near the web. Males and females are approximately the same size, and the males possess no sexual modifications on the legs. Description. Total length 7.0–15.1 mm. Carapace brownish, paler anteriorly, shiny, smooth, narrowed anteriorly at level of leg I (Fig. 255). Eyes approximately equal in size (Fig. 256); posterior row somewhat procurved; posterior median eyes somewhat less than their diameter apart, about 1.5 diameters from posterior lateral eyes; posterior median and anterior and posterior lateral eyes with canoe-shaped tapetum. Chelicerae (Fig. 256) long, rather stout; promargin of fang furrow with 3 teeth, retromargin with 4 teeth. Legs brownish, usually with indistinct dark rings (Figs. 255, 257); legs I longest. Abdomen with paired series of large dark spots on brownish background, broadly elliptical, plump, approximately as high as long, not greatly overhanging carapace (Fig. 255); venter gray to black, usually with paired well-separated white longitudinal bands. Palpus of male (Figs. 262, 263) with large lobed paracymbium; tegulum stout, curved; embolus large, curved; conductor and embolus arising laterally on genital bulb and terminating together at tip; embolus with complex apophysis. Epigynum (Figs. 258–261) with bulging median prominence; spermathecae small, angular or rounded, well separated (Fig. 260). Comments. Members of the genus Meta are distinguished from those of other tetragnathids by the high plump abdomen, by the paired large dark spots on the abdominal dorsum, by the complex embolar apophysis, and by the small, angular or rounded, well-separated spermathecae. The tendency toward living in moist dark habitats is also unusual among orb weavers. The genus probably comprises a dozen world species or less, many of those originally placed there having been transferred elsewhere by revisers. Levi (1980) revised the two known species in North America, one of which is represented in Canada.

Meta ovalis (Gertsch) Figs. 255–263; Map 28

Meta menardii: Emerton 1875:129; 1884:328, Figs. 18–18a (pl. 34), 33 (pl. 37); Gertsch and Ivie 1936:20; Kaston 1948:223, Figs. 700–703 (pl. 33); Levi 1980:42, Figs. 112–127. Auchicybaeus ovalis Gertsch, 1933:11, Fig. 15. Meta americana Marusik and Koponen, 1992:138, Figs 1–4, 14. Meta ovalis: Platnick 1993:376. Dondale 1995:125.

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Figs. 255–263. Meta ovalis. 255, female, dorsal view; 256, eyes and chelicerae of female, anterior view; 257, female, lateral view; 258, 259, 261, epigynum: 258, ventral view; 259, posterior view; 261, lateral view; 260, spermathecae; 262, 263, palpus of male: 262, ventral view; 263, retrolateral view. con, conductor; e, embolus; el, embolar lamella; pc, paracymbium; teg, tegulum.

Male. Total length 8.43 ± 1.39 mm; carapace 4.32 ± 0.45 mm long, 3.32 ± 0.47 mm wide (10 specimens measured). Carapace brownish, glabrous. Legs brownish, with indistinct darker rings; tibiae with two rows of dorsal trichobothria on basal half; basitarsi I–III with a dorsal trichobothrium near base. Abdomen (Figs. 255, 257) large, plump, dark, with large paired darker spots anteriorly; venter with paired longitudinal white bands. Palpus of male (Figs. 262, 263) with

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Map 28. Collection localities of Meta ovalis.

large paracymbium; paracymbium protruding laterally, with two blunt divergent processes on basal half of distal edge, and with tip broadly folded; conductor with distal row of short denticles; embolar apophysis forked at tip. Female. Total length 11.07 ± 1.31 mm; carapace 4.53 ± 0.54 mm long, 3.66 ± 0.62 mm wide. (10 specimens measured). Coloration and leg trichobothria as in male (Figs. 255, 257). Epigynum (Figs. 258–261) with bulging median hairy prominence; copulatory openings situated on posterior surface of median prominence; spermathecae (Fig. 260) small, ovoid, well separated. Range. North shore of Lake Superior to Newfoundland, south to eastern Oklahoma and northern Georgia. The species was until recently thought to be an introduction of the European M. menardii (Latreille) (Gertsch 1979:172, Levi 1980:42), but Marusik and Koponen (1992) gave characters for distinguishing specimens of the European and American species. Comments. Specimens of M. ovalis are distinguished from those of other species in the genus by the forked embolar apophysis, by the position and shape

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of the two blunt processes on the distal edge of the paracymbium, and by the hairiness of the epigynal prominence. There appears to be a size difference between specimens of the European M. menardii and those of the American M. ovalis, but no quantitative measurements are available for the former. Biology. Kaston (1948) gave the habitat as caves and abandoned mine shafts as well as damp ravines and overhanging stream banks. Mature males have been collected from May to December, mature females from February to November. Juveniles of various sizes occur in all months. Egg sacs are found from June to September; they are large, white, loosely spun, and partly transparent, and are suspended on a thread near the web. Emerton (1902) states that the web is vertical or nearly so, and has a small central spiral with the hub open.

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Family Araneidae Members of the family Araneidae include the largest and most imposing of the orb weavers. Some are well-known inhabitants of back yards and parks (e.g., Araneus diadematus) and others may be commonly seen in meadows or abandoned fields (e.g., Argiope spp.). Diverse in structure and behavior, they occupy grasslands, shrubs, tree tops, buildings, fences, and bridges, sometimes in impressive aggregations. Many spin large regular orb webs, and may build a silk-lined retreat from which they maintain contact with the web via a signal thread. A few make modified webs such as those of Zygiella spp., which have a missing sector. Some tropical araneids exhibit even more extreme kinds of web, and some use prey-capture methods other than trapping with webs. Description. Carapace yellowish to brown, usually low, narrowed toward front, sometimes ovoid (Figs. 291, 316, 337, 418); front usually not higher than diameter of an anterior median eye. Eyes approximately equal in size, or median eyes somewhat larger than lateral eyes; anterior median eyes often protruding anteriorly, and lateral eyes sometimes situated together on small tubercle (Figs. 651, 677). Legs yellowish, brown or orange, usually with dark rings; leg I usually longer than leg IV (exceptions: adults of Micrathena spp. and Cercidia spp.); coxa I of males often with hook, and femur II with corresponding groove; tibia II often expanded, curved, and armed with stout macrosetae. Abdomen spherical, elliptical, or angular, rarely long and slender, convex or flattened dorsally, rarely with one or more large angular tubercles at posterior end, and sometimes with paired humps anterolaterally, rarely spiny, usually with colorful pattern. Palpus of male (Figs. 393, 394) usually with 1–3 patellar macrosetae; genital bulb often compact, with sclerites facing midline of body; median apophysis usually with one or more slender pointed spurs, sometimes bifid, rarely oriented longitudinally on bulb; embolus often concealed by other sclerites, sometimes with basal lamella, sometimes with “cap” in unmated males, rarely long and threadlike; conductor variously shaped, sometimes with small spine at base; terminal apophysis often an imposing prong curving over tip of genital bulb (Fig. 463), rarely minute or absent; subterminal apophysis, if present, usually platelike; paracymbium small, basal, conical, fingerlike or hooked. Epigynum (Figs. 273, 342, 389, 483, 484) usually with scape; scape usually extending posteriorly over venter of abdomen, often with many transverse ridges and grooves (in absence of scape, a median septum may be present); posterior plate vaseshaped or V-shaped (Fig. 343), sometimes angular (Fig. 287); spermathecae (Figs. 275, 296, 352, 564, 609, 637) round, elliptical, kidney-shaped, or dumbbell-shaped, sometimes subdivided. Comments. Although there are several characters unique to at least some representatives of the Araneidae, none is clearly diagnostic for all of them. The coxal hook on leg I of males, which fits into a groove on femur II, thus locking

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legs I and II together during mating, is absent in representatives of five of the genera treated in this work, and absent in those of some species of two others. Likewise the possession of a terminal apophysis in the male palpus is only partly diagnostic, and is complicated moreover by the possibility of homologues of this sclerite in the palpi of males in other araneoid families (Coddington 1990a). The wrap attack, by which a spider first wraps its prey with silk before delivering a venomous bite, also is far from universal among members of the Araneidae, and, in addition, is found in at least some members of the Deinopoidea. The tapetum in the posterior median eyes of araneids is reduced to a “sliver” that lies across the middle of the eye, with the rhabdoms arranged in loops on one side only (Levi and Coddington 1983, Coddington 1990a). How pervasive this character is among the vast number of species of Araneidae remains to be determined. Coddington (1990a) proposes other potentially useful characters for the family, including palpal conformation (the orientation of the sclerites in relation to one another), the presence of a small sclerite called the radix interposed between the tegulum and embolus, and the possession of a distal haematodocha. These characters have not proven of much value in classification (Hormiga et al. 1995, Scharff and Coddington 1997). The family Araneidae is third largest in the world, including some 166 genera and 2789 catalogued species. There are about 30 genera and 165 species in America north of Mexico (Levi 2002b). The Canadian fauna comprises 19 genera and 62 species.

Key to genera of Araneidae 1.

Carapace with forked tubercules (Figs. 264, 265) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Mastophora (p. 129)

1'.

Carapace lacking forked tubercules . . . . . . . . . . . . . . . . . . . . . . . .2

2(1').

Tibia III with cluster of feathery trichobothria (Figs. 272, 279) . . . . . . . . . . . . . . . . . . . . . . . .Mangora O. Pickard- Cambridge (p. 133)

2'.

Tibia III without cluster of feathery trichobothria . . . . . . . . . . . . . .3

3(2').

Spinnerets surrounded by ring-shaped sclerite (Fig. 301). Abdomen of female with paired posteriorly directed spines (Figs. 291, 299, 307) . . . . . . . . . . . . . . . . . . . . . . . .Micrathena Sundevall (p. 141)

3'.

Spinnerets not surrounded by ring-shaped sclerite. Abdomen of female without posteriorly directed spines . . . . . . . . . . . . . . . . . . .4

4(3').

Posterior row of eyes distinctly procurved (dorsal view) (Figs. 314, 315, 330) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

4'.

Posterior row of eyes straight or recurved . . . . . . . . . . . . . . . . . . .6

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5(4).

Male tibia I curved, bearing stouter macrosetae than other leg tibiae. Lateral eyes (both sexes) on each side touching (Figs. 314, 315, 316) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Gea C.L. Koch (p. 150)

5'.

Male tibia I straight, with macrosetae similar in thickness to those on other leg tibiae. Lateral eyes eyes (both sexes) on each side well separated (Figs. 324, 330) . . . . . . . . . . . . . .Argiope Audouin (p. 153)

6(4').

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

6'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

7(6).

Coxa I with hook at tip, and femur I with corresponding groove (Fig. 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

7'.

Coxa I without hook, and femur I without groove . . . . . . . . . . . .16

8(7).

Palpal femur with small tooth, ventrally . . . . . . . . . . . . . . . . . . . . .9

8'.

Palpal femur without tooth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

9(8).

Palpal patella with 2 or more large macrosetae dorsally . . . . . . . .10

9'.

Palpal patella with 1 large macroseta dorsally (Fig. 339) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Cyclosa Menge (p. 160)

10(9).

Tegulum of palpus occupying nearly all of exposed surface of genital bulb, and embolus and conductor minute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Neoscona Simon (p. 166)

10'.

Tegulum of palpus occupying small part of exposed surface of genital bulb, and embolus and conductor larger (Figs. 393, 401, 423, 433) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

11(10').

Median apophysis with 2 long sinuous diverging spurs at base (Figs. 385, 393) . . . . . . . . Aculepeira Chamberlin & Ivie (p. 175)

11'.

Median apophysis without long curved sinuous spurs at base . . . .12

12(11').

Median apophysis thick, with deep cleft marking off slender piece (Figs. 400, 407, 415) . . . . . . . . .Larinioides di Caporiacco (p. 182)

12'.

Median apophysis thinner, without cleft . . . . . . . . . . . . . . . . . . . .13

13(12').

Abdomen pale, with 3 or more pairs of small circular black spots at posterolateral margins (Figs. 417, 418) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Araniella Chamberlin & Ivie (p. 191)

13'.

Abdomen usually pigmented and without pairs of small circular black spots at posterolateral margins, except Araneus cingulatus and A. guttulatus (Figs. 575, 576, 583–585) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Araneus Clerck (part) (p. 198)

14(8').

Palpal patella with 2 large dorsal setae . . .Cercidia Thorell (p. 261)

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14'.

Palpal patella with 1 large dorsal seta, or with 1 large and 1 small, or with 2 small macrosetae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

15(14').

Median apophysis colorless, cylindrical, attached to margin of genital bulb, directed basally (Figs. 610, 611, 620, 621, 630, 631) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Eustala Simon (p. 264)

15'.

Median apophysis pigmented, not cylindrical, not attached to margin of genital bulb nor directed basally . . . . . .Singa C.L. Koch (p. 274)

16(7').

Front 1.5–2.0 times higher than diameter of anterior median eyes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hypsosinga Ausserer (p. 280)

16'.

Front lower than diameter of anterior median eyes . . . . . . . . . . . .17

17(16').

Cymbium of palpus oriented mesally (Figs. 731, 738, 747); web with all sectors intact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

17'.

Cymbium of palpus oriented ventrally (Figs. 702, 709, 724); web with sector missing (Fig. 697) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Zygiella F.O. Pickard-Cambridge (p. 294)

18(17).

Margins of abdomen with stout spines (Fig. 726) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Acanthepeira Marx (p. 309)

18'.

Margins of abdomen without spines . . . . . . . . . . . . . . . . . . . . . . .19

19(18').

Abdomen elongate, slender (Figs. 733, 734). Median apophysis broadly forked (Fig. 738) . . . . . . . . . . . . . . .Larinia Simon (p. 312)

19'.

Abdomen ovoid or rounded. Median apophysis not broadly forked . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

20(19').

Median apophysis with 2 slender curved diverging spurs at basal end (Figs. 755, 757). Leg basitarsus plus distitarsus longer than patella plus tibia . . . . . . . . . . Metepeira F.O. Pickard-Cambridge (p. 315)

20'.

Median apophysis without curved diverging spurs at basal end. Leg basitarsus plus distitarsus shorter than patella plus tibia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Araneus Clerck (part) (p. 198)

21(6').

Front 1.5–2.0 times as high as diameter of anterior median eyes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hypsosinga Ausserer (p. 280)

21'.

Front much lower, approximately as high as diameter of anterior median eyes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

22(21').

Epigynal scape directed anteriorly (Figs. 606, 607, 616, 617, 626, 627) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Eustala Simon (p. 264)

22'.

Epigynal scape directed ventrally or posteriorly, or absent . . . . . .23 123

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23(22').

Carapace glabrous, dark anteriorly and paler posteriorly (Figs. 632, 634) . . . . . . . . . . . . . . . . . . . . . . . . . . . .Singa C.L. Koch (p. 274)

23'.

Carapace with setae or, if glabrous, not dark anteriorly and paler posteriorly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

24(23').

Abdomen with distinct angular hump posteriorly (lateral view, Fig. 338) . . . . . . . . . . . . . . . . . . . . . . . . . .Cyclosa Menge (p. 160)

24'.

Abdomen without angular hump posteriorly . . . . . . . . . . . . . . . .25

25(24').

Epigynum broadly heart-shaped. Scape short, straight (Figs. 397, 404, 412) . . . . . . . . . . . . . . . . . Larinioides di Caporiacco (p. 182)

25'.

Epigynum not heart-shaped. Scape longer, curved . . . . . . . . . . . .26

26(25').

Scape smooth (Figs. 356, 357, 519, 520, 728) . . . . . . . . . . . . . . .27

26'.

Scape with transverse ridges and grooves (Figs. 381, 389, 419, 452, 595, 743) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

27(26).

Abdomen with spines at margins (Fig. 726) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acanthepeira Marx (p. 309)

27'.

Abdomen without spines at margins . . . . . . . . . . . . . . . . . . . . . . .28

28(27').

Venter of abdomen with 2 pairs of white spots separated by median black band. Scape long, spatula-shaped (Figs. 356, 364, 373) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Neoscona Simon (p. 166)

28'.

Venter of abdomen with different pattern, or with none. Scape shorter, not spatula-shaped (Figs. 519, 520) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Araneus Clerck (part) (p. 198)

29(26').

Abdomen with short stiff macrosetae anteriorly (Fig. 593) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Cercidia Thorell (p. 261)

29'.

Abdomen without cluster of conspicuous macrosetae anteriorly . .30

30(29').

Abdomen long and narrow, with pattern of longitudinal lines (Fig. 733) . . . . . . . . . . . . . . . . . . . . . . . . . .Larinia Simon (p. 312)

30'.

Abdomen ovoid or rounded, not lined . . . . . . . . . . . . . . . . . . . . .31

31(30').

Abdomen with 3 (rarely 4) pairs of small circular black spots at posterolateral margins (Figs. 417, 418) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Araniella Chamberlin & Ivie (p. 191)

31'.

Abdomen lacking 3 (or 4) pairs of small circular black spots at posterolateral margins (spots may appear in other positions) . . . . . . .32

32(31').

Leg basitarsus plus distitarsus longer than patella plus tibia . . . . . . . . . . . . . . . . . . . . . . . . Metepeira F.O. Pickard-Cambridge (p. 315)

124

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32'.

Leg basitarsus plus distitarsus shorter than patella plus tibia . . . .33

33(32').

Dorsum of abdomen with pale pattern on dark background (Figs. 379, 387) . . . . . . . . . Aculepeira Chamberlin & Ivie (p. 175)

33'.

Dorsum of abdomen with dark pattern on pale background (Figs. 429, 451, 517, 698, 704), or without pattern (Figs. 546, 553) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

34(33').

Abdomen elliptical, rather flat dorsally (Fig. 698). Epigynum without scape (in Canadian species) (Figs. 699, 706, 711, 719). Web with missing sector (Fig. 697) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Zygiella F.O. Pickard-Cambridge (p. 294)

34'.

Abdomen round or approximately triangular. Epigynum with scape. Web complete . . . . . . . . . . . . . . . .Araneus Clerck (part) (p. 198)

Clé des genres d’Araneidae 1.

Céphalothorax muni de tubercules fourchus (figs. 264, 265) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mastophora (p. 129)

1'.

Céphalothorax dépourvu de tubercules . . . . . . . . . . . . . . . . . . . . . .2

2.

Tibia III portant une touffe de trichobotries plumeuses (figs. 272, 279) . . . . . . . . . . . . . . . . Mangora O. Pickard-Cambridge (p. 133)

2'.

Tibia III sans touffe de trichobotries plumeuses . . . . . . . . . . . . . . .3

3(2').

Présence d’un sclérite annulaire qui entoure les filières (fig. 301). Abdomen des femelles munis d’éperons pointant vers l’arrière . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Micrathena Sundevall (p. 141)

3'.

Absence d’un sclérite annulaire qui entoure les filières. Abdomen des femelles dépourvu d’éperons pointant vers l’arrière (figs. 291, 299, 307) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

4(3').

Rangée postérieure des yeux nettement procurvée (en vue dorsale) (figs. 314, 315, 330) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

4'.

Rangée postérieure des yeux formant une ligne droite ou récurvée . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

5(4).

Tibia I du mâle recourbé, portant des soies articulées plus robustes que les autres tibias . Yeux latéraux contigus (figs. 314, 315, 316) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Gea C.L. Koch (p. 150)

5'.

Tibia I du mâle droit, portant des soies articulées semblables aux autres tibias. Yeux latéraux bien distancés les uns des autres (figs. 324, 330) . . . . . . . . . . . . . . . . . . . .Argiope Audouin (p. 153)

125

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6(4').

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

6'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

7(6).

Extrémité de la coxa I munie d’un crochet et fémur I comprenant le sillon correspondant (fig. 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

7'.

Coxa I sans crochet et fémur I sans sillon . . . . . . . . . . . . . . . . . .16

8(7).

Fémur du palpe muni d’une petite dent . . . . . . . . . . . . . . . . . . . . .9

8'.

Fémur du palpe sans dent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

9(8).

Partie dorsale de la patella du palpe portant 2 soies articulées ou plus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

9'.

Partie dorsale de la patella du palpe portant une seule grosse soie articulée (fig. 339) . . . . . . . . . . . . . . . . . .Cyclosa Menge (p. 160)

10(9).

Tégulum du palpe occupant presque toute la surface visible du bulbe génital, embolus et conducteur minuscules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Neoscona Simon (p. 166)

10'.

Tégulum du palpe occupant une petite partie de la surface visible du bulbe génital, embolus et conducteur plus robustes (figs. 393, 401, 423, 433) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

11(10').

Base de l’apophyse médiane armée de 2 longs éperons recourbés qui pointent dans des directions opposées (figs. 385, 393) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aculepeira Chamberlin & Ivie (p. 175)

11'.

Apophyse médiane sans longs éperons recourbées . . . . . . . . . . . .12

12(11').

Apophyse médiane large, portant une fente profonde qui délimite deux parties (figs. 400, 407, 415) Larinioides di Caporiacco (p. 182)

12'.

Apophyse médiane plus mince et sans fente . . . . . . . . . . . . . . . . .13

13(12').

Abdomen blanchâtre, arborant 3 paires (ou plus) de petites taches circulaires noires sur la marge postéro-latérale (figs. 417, 418) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Araniella Chamberlin & Ivie (p. 191)

13'.

Abdomen habituellement pigmenté mais sans petites taches noires et rondes sur la marge postéro-latérale sauf Araneus cingulatus et A. guttulatus (figs. 575, 576, 583–585 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Araneus Clerck (en partie) (p. 198)

14(8').

Partie dorsale de la patella du palpe portant 2 grandes soies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Cercidia Thorell (p. 261)

14'.

Partie dorsale de la patella du palpe portant 1 seule grande soie, 1 grande et 1 petite, ou deux petites . . . . . . . . . . . . . . . . . . . . . . . .15

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15(14').

Apophyse médiane incolore, de forme cylindrique, joignant le bulbe génital par la marge et orientée vers le bas (figs. 610, 611, 620, 621, 630, 631) . . . . . . . . . . . . . . . . . . . . . . . . . .Eustala Simon (p. 264)

15'.

Apophyse médiane colorée, non cylindrique, ne joignant pas le bulbe génital par la marge et non orientée vers le bas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Singa C.L. Koch (p. 274)

16(7').

Hauteur de la région entre les yeux antérieurs et la marge antérieure du céphalothorax 1.5 à 2.0 fois plus grande que le diamètre des yeux antérieurs médians . . . . . . . . . . . . . . Hypsosinga Ausserer (p. 280)

16'.

Hauteur de la région entre les yeux antérieurs et la marge antérieure du céphalothorax similaire au diamètre des yeux antérieurs médians . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

17(16').

Cymbium du palpe orienté dans un axe médian (figs. 731, 738, 747); toile dont tous les secteurs sont présents . . . . . . . . . . . . . . . . . . .18

17'.

Cymbium du palpe orienté dans un axe dorso-ventral (figs. 702, 709, 724); toile caractérisée par un secteur manquant (fig. 697) . . . . . . . . . . . . . . . . . . . . . . . . . . .Zygiella F.O. Pickard-Cambridge (p. 294)

18(17).

Rebord de l’abdomen muni de plusieurs protubérances pointues (fig. 726) . . . . . . . . . . . . . . . . . . . . . . Acanthepeira Marx (p. 309)

18'.

Rebord de l’abdomen sans de telles protubérances . . . . . . . . . . . 19

19(18').

Abdomen allongé et étroit (figs. 733, 734). Apophyse médiane grossièrement fourchue (fig. 738) . . . . . . . .Larinia Simon (p. 312)

19'.

Abdomen arrondi ou ovoïde. Apophyse médiane sans fourche . . 20

20(19').

Point d’attache de l’apophyse médiane munie de 2 éperons minces, recourbés et divergents (figs. 755, 757). Somme des longueurs du basitarse et du distitarse plus grande que la somme des longueurs de la patella et du tibia . . . Metepeira F.O. Pickard-Cambridge (p. 315)

20'.

Point d’attache de l’apophyse médiane muni d’un seul éperon. Somme des longueurs du basitarse et du distitarse plus petite que la somme des longueurs de la patella et du tibia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Araneus Clerck (en partie) (p. 198)

21(6').

Hauteur de la région entre les yeux antérieurs et la marge antérieure du céphalothorax 1.5 à 2.0 fois plus grande que le diamètre des yeux antérieurs médians . . . . . . . . . . . . . . Hypsosinga Ausserer (p. 280)

21'.

Hauteur de la région entre les yeux antérieurs et la marge antérieure du céphalothorax similaire au diamètre des yeux antérieurs médians . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

127

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22(21').

Scape de l’épigyne pointant vers la partie antérieure (figs. 606, 607, 616, 617, 626, 627) . . . . . . . . . . . . . . . . . . Eustala Simon (p. 264)

22'.

Scape de l’épigyne pointant ventralement, vers la partie postérieure, ou scape absent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

23(22').

Céphalothorax glabre, coloration sombre dans la partie antérieure et pâle dans la partie postérieure (figs. 632, 634) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Singa C.L. Koch (p. 274)

23'.

Céphalothorax portant des soies. Si glabre, d’une coloration différente . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

24(23').

Partie terminale de l’abdomen portant une protubérance distincte formant un angle (vue latérale, fig. 338) . . . .. Cyclosa Menge (p. 160)

24'.

Partie terminale de l’abdomen sans protubérance . . . . . . . . . . . . 25

25(24').

Épigyne cordiforme. Scape court et droit (figs. 397, 404, 412) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Larinioides di Caporiacco (p. 182)

25'.

Épigyne non cordiforme. Scape long et recourbé . . . . . . . . . . . . 26

26(25').

Scape lisse (figs. 356, 357, 519, 520, 728) . . . . . . . . . . . . . . . . . 27

26'.

Scape possédant des carènes et des sillons transverses (figs. 381, 389, 419, 452, 595, 743) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

27(26).

Rebord de l’abdomen muni de plusieurs protubérances pointues (fig. 726) . . . . . . . . . . . . . . . . . . . . . . Acanthepeira Marx (p. 309)

27'.

Rebord de l’abdomen sans de telles protubérances . . . . . . . . . . . .28

28(27').

Surface ventrale de l’abdomen ornée de 2 paires de taches blanches divisées par une bande médiane noire. Scape long, en forme de spatule (figs. 356, 364, 373) . . . . . . . . . . . . . Neoscona Simon (p. 166)

28'.

Surface ventrale de l’abdomen ornée d’un assortiment de couleurs différent ou sans motifs. Scape court et d’une forme n’évoquant pas une spatule (figs. 519, 520) . . . .Araneus Clerck (en partie) (p. 198)

29(26').

Partie antérieure de l’abdomen munie de plusieurs courtes soies articulées et robustes (fig. 593) . . . . . . . . . . . .Cercidia Thorell (p. 261)

29'.

Partie antérieure de l’abdomen sans soies articulées . . . . . . . . . . 30

30(29').

Abdomen allongé et étroit, orné de traits longitudinaux (fig. 733) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Larinia Simon (p. 312)

30'.

Abdomen arrondi ou ovoïde, sans traits longitudinaux . . . . . . . . 31

31(30').

Abdomen arborant 3 paires (rarement 4) de petites taches noires et circulaires à la marge postéro-latérale (figs. 417, 418) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Araniella Chamberlin & Ivie (p. 191)

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31'.

Abdomen dépourvu de 3 paires (ou 4) de petites taches noires et circulaires à la marge postéro-latérale (des taches peuvent se trouver ailleurs sur l’abdomen) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

32(31').

Somme des longueurs du basitarse et du distitarse plus grande que la somme des longueurs de la patella et du tibia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Metepeira F.O. Pickard-Cambridge (p. 315)

32'.

Somme des longueurs du basitarse et du distitarse plus petite que la somme des longueurs de la patella et du tibia . . . . . . . . . . . . . . . 33

33(32').

Partie dorsale de l’abdomen arborant un assortiment de couleurs pâles sur un fond sombre (figs. 379, 387) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Aculepeira Chamberlin & Ivie (p. 175)

33'.

Partie dorsale de l’abdomen arborant un assortiment de couleurs sombres sur un fond de couleur pâle (figs. 429, 451, 517, 698, 704), ou sans motifs (figs. 546, 553) . . . . . . . . . . . . . . . . . . . . . . . . . . 34

34(33').

Abdomen en forme d’ellipse, surface dorsale aplatie (fig. 698). Épigyne sans scape (pour les espèces trouvées au Canada) (figs. 699, 706, 711, 719). Toile caractérisée par une section manquante (fig. 697) . . . . . . . . . . . . . . . . . . . . Zygiella F.O. Pickard-Cambridge (p. 294)

34'.

Abdomen arrondi, ou presque triangulaire. Épigyne munie d’un scape . . . . . . . . . . . . . . . . . . . . .Araneus Clerck (en partie) (p. 198)

Genus Mastophora Holmberg Representatives of the genus Mastophora, though in structure clearly belonging in the Family Araneidae, display a number of unusual behaviors. One such behavior is the replacement of prey-catching webs with a device known as a bolas. As the name suggests, the spider produces a ball of sticky silk at the end of a silk line. The ball is swung at an approaching moth and sticks to the moth’s body, arresting flight. The spider then descends the silk line and kills the moth with a venomous bite, after which the moth is wrapped and eaten. (Charles E. Hutchinson, in Gertsch 1955). Between captures the spider remains motionless on a twig or branch, with the bolas suspended from one front leg. After a time, the bolas may be drawn up and consumed, then replaced by a freshly spun one; this is thought to restore any lost stickiness to the bolas’ surface. Stowe (1986) believes that the bolas spiders can produce chemical compounds that have the same effect on male moths as the sex pheromones produced by females of these moths. Male moths are attracted upwind to the waiting spider. No glands have been found to produce these compounds, though Stowe reasons that they are more likely found on the spider’s body than on the bolas. 129

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A second observation regarding bolas spiders is their resemblance to other objects in the environment. Individuals of one species are said to resemble snails, of others lumps of bird dung, fruits, or a cat’s head (Gertsch 1955). Another unusual behavior is the precocious development of males (Kaston 1948, Gertsch 1955, Stowe 1986). Gertsch (1955) reported a brood of 75 mature males and 72 young juvenile females that emerged from a single egg sac of M. cornigera (Hentz). Gertsch inferred only two molts, both within the sac, for the males instead of a number more nearly like that of females. The females were assumed to require several more molts to reach sexual maturity. One species of Mastophora has the reputation of being venomous. This South American member of the genus lives in vineyards where they closely resemble living buds on the grape vines. Vineyard workers have reported severe bites from these spiders (Escomel, in Gertsch 1955). Description. Total length of males 1.5–2.3 mm, of females 10.0–15.0 mm. Carapace approximately as wide as long, broadly rounded or truncate at posterior margin, approximately triangular in lateral view (Fig. 264), with conspicuous paired tubercles and with additional smaller tubercles elsewhere (Fig. 265); front vertical. Legs slender, the first pair much longer than the others. Abdomen short, broad, high, often with paired rounded humps or with folds, grooves, or similar features, smooth and shiny or covered with setae. Palpus of male (Fig. 267) with slender pointed embolus and prominent curved median apophysis. Epigynum (Figs. 268–270) small, with weakly developed median septum, and with inconspicuous hood or ridge at anterior margin; spermathecae small and round. Comments. Members of the genus Mastophora are readily distinguished from those of other araneid genera by the conspicuous forked tubercles on the carapace. The genus includes a known fauna of 19 species, all restricted to the New World. Five of these are represented in North America, and a single species occurs or probably occurs in Canada.

Mastophora hutchinsoni Gertsch Figs. 264–270; Map 29

Cyrtarachne cornigera: Kaston 1948: 231, figs. 741, 742, 2039. Mastophora hutchinsoni Gertsch, 1955: 236, figs. 10–14, 39, 47, 48; Levi, 2002a: 47, figs. 153–168, 453, 454. Male. Total length 1.70, 1.74 mm; carapace 0.83, 0.86 mm long, 0.66, 0.71 mm wide (2 specimens measured). Eyes minute (as in Fig. 265). Chelicerae small. Carapace dull reddish, paler mesally, with paired prominent forked tuber-

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Figs. 264–270. Mastophora hutchinsoni. 264, body of female, lateral view; 265, carapace, anterior view; 266, egg sac; 267, palpus of male, prolateral view; 268, epigynum, posterior view; 269, spermathecae; 270, epigynum, ventral view. e, embolus; ma, median apophysis; term, terminal apophysis.

cles and with few minute tubercles elsewhere; with few short setae. Abdomen approximately triangular in dorsal view, off-white, usually with small paired dorsal humps. Palpus (Fig. 267) with prominent bulging tegulum; terminal apophysis rounded; median apophysis prominent, with rounded base, curved distally; embolus slender; paracymbium short, fingerlike, situated on margin of cymbium near base of the latter. Female. Total length 7.30, 8.25 mm; carapace 2.99, 3.30 mm long, 2.70, 2.91 mm wide (2 specimens measured). Eyes and chelicerae as in male. Carapace dark reddish brown, somewhat paler mesally, with forked tubercles and with few smaller tubercles elsewhere (Fig. 265). Abdomen broader than long, yellowish or brownish, with paired white marks near middle, with broad dark transverse band across middle, and with paired large rounded humps (Fig. 264). Epigynum

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Map 29. Collection localities of Mastophora hutchinsoni.

(Figs. 268–270) often partly obscured in ventral view; median septum broad, widening posteriorly; spermathecae small, round. Range. Minnesota to Michigan and New Hampshire, south to South Carolina. Comments. Individuals of M. hutchinsoni are recognized by the prominent forked tubercles on the carapace and by the large rounded humps on the abdomen. Biology. Specimens of this spider have been collected from the lower branches of many kinds of deciduous trees, including fruit trees. Mature males have been recorded from June to September, mature females from September to November. Egg sacs, which are flask-shaped and fastened to twigs by many strong threads (Fig. 265), may be found in autumn and winter when the trees are leafless. Kaston (1948) recorded a sac with a diameter of about 8 mm and a neck about 6 mm long; it contained approximately 150 eggs.

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Genus Mangora O. Pickard-Cambridge Members of the genus Mangora are rather small orb weavers of fields or of the herb and shrub layers of deciduous forests. The orb web is vertical to horizontal, finely meshed, and has the hub filled with threads. There may be 50–60 radii and 50 or more sticky spirals. The spider builds no retreat but is found at the hub or on a nearby grass stem. Description. Total length 1.9–5.5 mm. Carapace approximately pear-shaped in outline, strongly narrowed anteriorly at sides, high at level of dorsal groove, gradually lower toward front (Fig. 272). Median eyes of both rows larger than laterals; posterior row straight or somewhat recurved. Legs slender, moderately long, with macrosetae conspicuous, partly erect (Fig. 272); tibia III with rows of feathery trichobothria prolaterally near base (Figs. 272, 279); coxa I of male with hook, and femur II with corresponding groove. Abdomen elliptical or ovoid, in the latter case widest in posterior half (Figs. 271, 278, 285), variously patterned according to species, often reflexed toward sternum. Palpus of male with 1 patellar macroseta, and with compact genital bulb (Figs. 276, 277, 283, 284, 289, 290); tegulum usually rather small, curved around base of bulb; median apophysis small, situated on mesal surface of bulb, with 1 or 2 small pointed spurs; embolus small to large, sometimes forked; conductor usually small; terminal apophysis often large, curved, hornlike. Epigynum usually with scape (Figs. 273, 280, 286), weakly sclerotized; posterior plate variously shaped according to species; spermathecae elliptical, round, or boot-shaped, nearly touching (Figs. 275, 282, 288). Comments. Specimens of the genus Mangora are distinguished from those of other araneid genera by the high, anteriorly sloping carapace, by the rows of feathery trichobothria on tibia III, and in part by the reflexed abdomen. A world fauna of less than 60 species is catalogued. Levi (1975a) revised seven species from America north of Mexico; three of these are represented in Canada.

Key to species of Mangora 1.

Femora I and II with black line ventrally; dorsum of abdomen with 2 or 3 black longitudinal lines (Fig. 271) . . . . gibberosa (Hentz) (p. 134)

1'.

Femora I and II lacking black lines ventrally; dorsum of abdomen with series of paired spots (Figs. 278, 285) . . . . . . . . . . . . . . . . . 2

2(1').

Dorsum of abdomen with paired black spots extending over nearly entire length (Fig. 278) . . . . . . . . . . . . . . . placida (Hentz) (p. 136)

2'.

Dorsum of abdomen with 3 pairs of black spots situated at posterior end of abdomen (Fig. 285) . . . . . . maculata (Keyserling) (p. 139)

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Clé des espèces de Mangora 1.

Face ventrale des fémurs I et II ornée d’un trait noir; partie dorsale de l’abdomen arborant 2 ou 3 traits noirs longitudinaux (fig. 271) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gibberosa (Hentz) (p. 134)

1'.

Fémurs I et II sans trait noir, partie dorsale de l’abdomen ornée de deux rangées de taches (figs. 278, 285) . . . . . . . . . . . . . . . . . . . . 2

2(1').

Abdomen orné d’une série de taches noires qui s’étend sur presque toute la longueur (fig. 278) . . . . . . . . . . . . placida (Hentz) (p. 136)

2'.

Abdomen orné de 3 paires de taches noires localisées sur la partie postérieure (fig. 285) . . . . . . . . . . maculata (Keyserling) (p. 139)

Mangora gibberosa (Hentz) Lined Orbweaver Figs. 271–277; Map 30

Epeira gibberosa Hentz, 1847:477, fig. 20 (pl. 31); Emerton 1885:317, figs. 1 (pl. 34), 17 (pl. 36). Mangora gibberosa: Comstock 1913:505, figs. 541–543; Kaston 1948:239, figs. 743, 744 (pl. 35), 755, 756 (pl. 36), 2042 (pl. 122); Levi 1975a:130, plate 2, figs. 118–130. Male. Total length 2.86 ± 0.16 mm; carapace 1.45 ± 0.12 mm long, 1.14 ± 0.10 mm wide (10 specimens measured). Carapace pale yellowish or pale green, with slender black median longitudinal stripe. Legs yellowish; femora I and II with slender black line ventrally; tibia III with about 10 feathery trichobothria (Fig. 272). Abdomen elliptical, yellowish to pale green, with 2 or 3 black longitudinal lines (Fig. 271). Palpus with 1 patellar macroseta; median apophysis with 2 small pointed spurs (Figs. 276, 277); embolus large, deeply forked (Fig. 276). Female. Total length 3.81 ± 0.54 mm; carapace 1.61 ± 0.14 mm long, 1.25 ± 0.15 mm wide (10 specimens measured). Coloration of carapace, legs, and abdomen as in male (Figs. 271, 272). Epigynum with scape; scape attached at anterior margin of epigynal plate, broad anteriorly, tapered to spoonlike tip (Fig. 273); posterior plate long, slender, expanded laterally at posterior end (Fig. 274); spermathecae large, elliptical, oblique (Fig. 275). Range. North Dakota to Ontario and Maine, south to eastern Texas and Florida. Comments. Specimens of M. gibberosa are distinguished from those of other species of Mangora by the black lines on the ventral surface of femora I and

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Figs. 271–277. Mangora gibberosa. 271, abdomen of female, dorsal view; 272, female, lateral view; 273, 274, epigynum: 273, ventral view; 274, posterior view; 275, spermathecae; 276, 277, palpus of male: 276, mesal view; 277, ventral view. e, embolus; ls, lateral sclerite; ma, median apophysis; pp, posterior plate; s, scape; spt, spermatheca; teg, tegulum; term, terminal apophysis; trich, trichobothria.

II, by the black lines on the abdominal dorsum, by the forked embolus, and by the anteriorly attached epigynal scape. Biology. Individuals of M. gibberosa are commonly collected in fields and in weedy places such as roadsides and the edges of deciduous forests. Adults are present from June to November. The webs are horizontal or inclined, and the spi-

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Map 30. Collection localities of Mangora gibberosa.

der may remain at the hub or move to the shelter of a curled leaf above the web. According to Kaston (1948), eggs are laid and hatched in autumn, and the young remain in the sac until the following spring.

Mangora placida (Hentz) Tuftlegged Orbweaver Figs. 278–284; Map 31

Epeira placida Hentz, 1847:475, fig. 12 (pl. 31); Emerton 1885:316, fig. 2 (pl. 34), 10, 13 (pl. 36). Epeira praetrepida Keyserling, 1881:549, fig. 2 (pl. 16). Mangora placida: Comstock 1913:505, fig. 544; Kaston 1948:238, figs. 753, 754 (pl. 36); Levi 1975a:126, figs. 80, 81, 90–101. 136

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Figs. 278–284. Mangora placida. 278, abdomen of female, dorsal view; 279, tibia III showing cluster of feathery trichobothria; 280, 281, epigynum: 280, ventral view; 281, posterior view; 282, spermathecae; 283, 284, palpus of male: 283, mesal view; 284, ventral view. e, embolus; ma, median apophysis; pp, posterior plate; spt, spermatheca.

Male. Total length 2.36 ± 0.26 mm; carapace 1.08 ± 0.09 mm long, 0.87 ± 0.04 mm wide (10 specimens measured). Carapace yellowish, with dark median longitudinal stripe and with dark lateral margins. Legs yellowish; tibia III with approximately 7 feathery trichobothria (Fig. 279). Abdomen elliptical to somewhat ovoid, with broad brownish midstripe; midstripe enclosing approximately 5 pairs of black spots; spots situated over nearly all of dorsum length (Fig. 278). Palpus with 1 patellar macroseta; median apophysis with 1 pointed spur (Figs. 283, 284); embolus broad, rather flat, blunt at tip (Fig. 284). 137

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Map 31. Collection localities of Mangora placida.

Female. Total length 3.12 ± 0.51 mm; carapace 1.26 ± 0.22 mm long, 0.97 ± 0.11 mm wide (10 specimens measured). Coloration of carapace, legs, and abdomen as in male (Fig. 278). Epigynum with scape; scape short, spoonlike, attached near posterior margin of epigynum (Fig. 280); posterior margins oblique, strongly sclerotized; posterior plate wider than long (Fig. 281); spermathecae ovoid, nearly touching (Fig. 282). Range. Manitoba to Nova Scotia, south to northeastern Mexico and Florida. Comments. Specimens of M. placida are distinguished from those of other species in the genus by the extensive paired black spots on the abdominal dorsum, by the broad blunt embolus, and by the oblique strongly sclerotized posterior margins of the epigynum. Biology. Individuals of M. placida are commonly collected in undergrowth plants in deciduous forests, but may also occur in tall grass. The web is vertical or somewhat inclined. Young individuals overwinter, and maturity is attained in the spring. 138

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Mangora maculata (Keyserling) Greenlegged Orbweaver Figs. 285–290; Map 32

Epeira maculata Keyserling, 1865:827, figs. 24–27 (pl. 18). Mangora maculata: Comstock 1913:507; Kaston 1948: 239, fig. 757 (pl. 36); Levi 1975a:122, figs. 58–68. Male. Total length 3.01 ± 0.23 mm; carapace 1.64 ± 0.10 mm long, 1.26 ± 0.09 mm wide (9 specimens measured). Carapace yellowish, with faint short midstripe. Legs yellowish; tibia III with approximately 11 feathery trichobothria near base. Abdomen whitish, with 3 pairs of small black spots near posterior end (Fig. 285). Palpus with 1 patellar macroseta; median apophysis with 2 short spurs (Fig. 290); embolus broad, truncate at tip (Fig. 289). Female. Total length 4.30 ± 0.51 mm; carapace 1.69 ± 0.10 mm long, 1.30 ± 0.09 mm wide (10 specimens measured). Coloration of carapace, legs, and abdomen as in male (Fig. 285). Epigynum with scape; scape short, approximate-

Map 32. Collection localities of Mangora maculata.

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Figs. 285–290. Mangora maculata. 285, abdomen of female, dorsal view; 286, 287, epigynum: 286, ventral view; 287, posterior view; 288, spermathecae; 289, 290, palpus of male: 289, ventrolateral view; 290, ventral view. e, embolus; ma, median apophysis; pp, posterior plate; spt, spermatheca.

ly even in width, spoonlike at tip, attached near middle of epigynal plate (Fig. 286); posterior plate broader than long (Fig. 287); spermathecae bootshaped (Fig. 288). Range. Northern Peninsula of Michigan to Massachusetts, south to eastern Texas and Florida. Comments. Specimens of M. maculata are distinguished from those of others in the genus by the 3 pairs of small black spots near the posterior end of the 140

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abdomen, by the broad truncated embolus, by the attachment of the scape near the middle of the epigynal plate, and by the boot-shaped spermathecae. Biology. Individuals of M. maculata have been collected in undergrowth plants in deciduous forests, particularly in the flood plains of rivers, as well as in ferns and sedges at the margins of swamps and bogs. Adults appear from early June to October.

Genus Micrathena Sundevall Members of the genus Micrathena are hard-bodied spiders commonly known as spiny-bellied orb weavers. The integument is hard and shiny, the abdomen extends posteriorly beyond the spinnerets, and the carapace and/or abdomen of females may bear pointed spines. Diurnal animals, they maintain the hunting posture at the hub of the web all day, maintaining tension on the web with their long powerful fourth pair of legs. There is no retreat beside the web. The web is closely meshed, has an open hub, and is made of many radii and spirals. Description. Total length 3.0–5.9 mm (males), 4.7–10.8 mm (females). Carapace longer than wide, hard, shiny, without setae, brownish with paler lateral margins, in females highest anteriorly and at dorsal groove, with depression anterior to groove (Figs. 291–293, 299, 300, 307, 308). Eyes small; posterior row of eyes straight or somewhat recurved; anterior median eyes larger than other eyes, or all eyes approximately equal in size. Legs brown or yellowish, without dark rings, with few or no macrosetae (Fig. 291); leg IV longer than other legs; coxa I of males sometimes with hook. Abdomen with sclerotized ring surrounding spinnerets (Fig. 301); in male with rather soft integument, lacking abdominal spines, truncated anteriorly and posteriorly (Figs. 292, 293, 300, 308); in female hard, shiny, pitted, with white, brown, or black pattern, with few or no setae, and with 2–5 pairs of stout pointed spines (Figs. 291, 299, 307). Palpus of male with 1 dorsal patellar macroseta (sometimes rather weak); tegulum large, convex, occupying much of genital bulb surface (Fig. 297); median apophysis minute, bearing slender spur, or larger and hooklike or bulbous (Fig. 298); embolus long, rather slender, pointed at tip, with large radix; conductor small, bulbous; terminal apophysis lacking; paracymbium often large, hooked, sometimes rugose (Figs. 297, 305, 312). Epigynum (Figs. 294, 295, 302, 303, 309, 310) strongly sclerotized, with knoblike projection; copulatory openings small, situated posteriorly at base of knoblike projection; spermathecae large, round, elliptical or elongate, touching or nearly touching at midline (Figs. 296, 304, 311). Comments. Specimens of Micrathena spp. are distinguished from those of other araneid genera by the sclerotized ring surrounding the base of the spinnerets, by the pale lateral margins of the carapace of female, by the peculiarly shaped paracymbium, and by the knoblike projection on the epigynum. The

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abdominal spines of females and the unusually long legs IV of both sexes are partly diagnostic. Micrathena is an American genus. Levi (1978) revised the four species represented in North America; three of these are represented in Canada.

Key to species of Micrathena 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2(1).

Abdomen widest posteriorly (Figs. 292, 293). Paracymbium curved dorsally (Fig. 297). Median apophysis subdivided (Fig. 298) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . sagittata Walckenaer (p. 143)

2'.

Abdomen widest near middle (Figs. 300, 308). Paracymbium curved ventrally (Fig. 305), or not curved (Fig. 312). Median apophysis not subdivided . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3(2').

Abdomen more than twice as long as carapace (Fig. 300). Spinnerets situated closer to genital groove than to posterior end of abdomen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gracilis Walckenaer (p. 146)

3'.

Abdomen at most 1.5 times as long as carapace (Fig. 308). Spinnerets closer to posterior end of abdomen than to genital groove . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . mitrata (Hentz) (p. 148)

4(1').

Abdomen with 5 pairs of conical spines (Fig. 299) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gracilis Walckenaer (p. 146)

4'.

Abdomen with 2 or 3 pairs of spines (Figs. 291, 307) . . . . . . . . . 5

5(4').

Abdomen with 2 pairs of spines (Fig. 307). Carapace with 3 pairs of dimples laterally (Fig. 307) . . . . . . . . . . . mitrata (Hentz) (p. 148)

5'.

Abdomen with 3 pairs of spines (Fig. 291). Carapace lacking dimples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . sagittata Walckenaer (p. 143)

Clé des espèces de Micrathena 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2(1).

Abdomen plus large dans la partie postérieure (figs. 292, 293). Paracymbium recourbé vers l’extérieur (fig. 297). Apophyse médiane divisée en deux parties (fig. 298) . . . . sagittata Walckenaer (p. 143)

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2'.

Abdomen plus large dans la partie médiane (figs. 300, 308). Paracymbium recourbé vers l’intérieur(fig. 305), ou non recourbé (fig. 312). Apophyse médiane entière . . . . . . . . . . . . . . . . . . . . . . 3

3(2').

Abdomen plus de 2 fois plus long que le céphalothorax (fig. 300). Filières se trouvant plus près du sillon génital que de l’extrémité de l’abdomen . . . . . . . . . . . . . . . . . . . . . gracilis Walckenaer (p. 146)

3'.

Abdomen au plus 1.5 fois plus long que le céphalothorax (fig. 308). Filières se trouvant plus près de l’extrémité de l’abdomen que du sillon génital . . . . . . . . . . . . . . . . . . . . . . . . mitrata (Hentz) (p. 148)

4(1').

Abdomen orné de 5 paires de protubérances coniques et pointues (fig. 299) . . . . . . . . . . . . . . . . . . . . . . gracilis Walckenaer (p. 146)

4'.

Abdomen orné de 2 ou 3 paires de protubérances coniques et pointues (figs. 291, 307) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

5(4').

Abdomen orné de 2 paires d’éperons et de protubérances coniques (fig. 307). Céphalothorax bordé de 3 fossettes latérales (fig. 307) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . mitrata (Hentz) (p. 148)

5'.

Abdomen orné de 3 paires d’éperons et de protubérances coniques (fig. 291). Céphalothorax sans fosette . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . sagittata Walckenaer (p. 143)

Micrathena sagittata (Walckenaer) Arrowshaped Micrathena Figs. 291–298; Map 33

Plectana sagittata Walckenaer, 1841:174. Epeira spinea Hentz, 1850:21, fig. 9 (pl. 3). Acrosoma bovinum Thorell, 1859:301. Acrosoma spinea: Emerton 1885:326, figs. 5–8 (pl. 38). Micrathena sagittata: F.O. Pickard-Cambridge 1904:536, figs. 20, 21 (pl. 51); Kaston 1948:219, figs. 690–693 (pl. 33), 2028 (pl. 116); Levi 1978:430, figs. 41–54. Micrathena comstocki Archer, 1951:10, figs. 15–17. Micrathena sagittata emertoni Archer, 1951:10, figs. 18, 22. Male. Total length 4.23, 4.57, 4.70 mm; carapace 1.86, 1.90, 1.91 mm long, 1.20, 1.29, 1.36 mm wide (3 specimens measured). Carapace brown. Legs brown. Abdomen black, with white marks at lateral margins and near posterior end, somewhat flattened dorsoventrally, widest at posterior end (Figs. 292, 293); venter black and brown. Palpus with 1 weak patellar macroseta; median apophysis

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Figs. 291–298. Micrathena sagittata. 291, female, dorsal view; 292, 293, male, dorsal views; 294, 295, epigynum: 294, ventral view; 295, lateral view; 296, spermathecae; 297, 298, palpus of male: 297, retrolateral view; 298, mesal view. e, embolus; ma, median apophysis; pc, paracymbium; spt, spermatheca; teg, tegulum.

divided into two bulbous parts (Fig. 298); embolus long, slender, somewhat ribbonlike; paracymbium long, stout, with tip curved dorsally (Fig. 297). Female. Total length 8.51 ± 1.18 mm; carapace 2.80 ± 0.25 mm long, 2.36 ± 0.47 mm wide (8 specimens measured). Carapace brown, with pale lateral mar144

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Map 33. Collection localities of Micrathena sagittata.

gins (Fig. 291). Legs brown. Abdomen white to yellow or orange, with black area at anterior end, and with three pairs of black spines (Fig. 291). Epigynum strongly convex, well sclerotized, with small pointed median projection (Figs. 294, 295); posterior sclerite slender, longer than wide, somewhat constricted at middle; spermathecae rounded, touching at midline (Fig. 296). Range. Minnesota to New Hampshire, south to Costa Rica. Comments. Specimens of M. sagittata are distinguished from those of other species in the genus by the posteriorly broad abdomen of the male, by the subdivided median apophysis, by the dorsally curved paracymbium, by the small slender epigynal projection, and by the slender posterior sclerite of the epigynum. Biology. Individuals of M. sagittata are found among shrubs and other understorey plants in open areas of deciduous forests. Adults appear in late July, and males persist into August, females until October (Kaston 1948). Eggs are covered with a “fluffy white shere” of silk (Kaston 1948). 145

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Micrathena gracilis (Walckenaer) Spined Micrathena Figs. 299–306; Map 34

Epeira gracilis Walckenaer, 1805:65. Plectana gracilis: Walckenaer 1841:193. Plectana reduviana Walckenaer, 1841:201. Epeira rugosa Hentz, 1850:21, fig. 10 (pl. 3). Acrosoma rugosa: Emerton 1885:326, fig. 10 (pl. 38). Micrathena gracilis: F.O. Pickard-Cambridge 1904:528, figs. 3 (pl. 50), 16 (pl. 51); Kaston 1948:219, figs. 688, 689 (pl. 33); Levi 1978:433, plate 1, figs. 55–68. Micrathena nigrior Chamberlin and Ivie, 1936:58, figs. 134, 135. Male. Total length 4.80, 4.81 mm; carapace 1.40, 1.41 mm long, 0.90, 0.91 mm wide (2 specimens measured). Carapace brown. Legs brown. Abdomen off-white, elongate (more than twice as long as carapace); venter dark; spinnerets

Map 34. Collection localities of Micrathena gracilis.

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Figs. 299–306. Micrathena gracilis. 299, female, dorsal view; 300, male, dorsal view; 301, spinnerets; 302, 303, epigynum: 302, ventral view; 303, posterior view; 304, spermathecae; 305, 306, palpus of male: 305, retrolateral view; 306, mesal view. e, embolus; ma, median apophysis; pc, paracymbium; scl, sclerite.

situated closer to genital groove than to tip of abdomen. Palpus with 1 weak patellar macroseta; median apophysis small, with slender filamentous spur (Fig. 306); embolus long, slender, pointed at tip (Fig. 306); paracymbium small, ventrally hooked (Fig. 305). 147

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Female. Total length 9.73 ± 1.29 mm; carapace 2.90 ± 0.20 mm long, 2.20 ± 0.22 mm wide (9 specimens measured). Carapace brown, with lateral margins pale. Legs brown. Abdomen off-white to nearly all black, with few small dark spots, and with 5 pairs of stout brown spines (Fig. 299). Epigynum with prominent, laterally flattened median projection (Fig. 302); posterior plate long, pointed at ventral end, abruptly narrowed at posterior end (Fig. 303); spermathecae round, nearly touching at midline (Fig. 304). Range. Wisconsin and southern Michigan to northern New York and Massachusetts, south to Panama. Comments. Specimens of M. gracilis are distinguished from those of other species in the genus by the greatly elongated abdomen and anterior position of the spinnerets in males, by the 5 pairs of abdominal spines in females, by the filamentous spur on the median apophysis, by the small ventrally hooked paracymbium, by the laterally flattened epigynal projection, and by the broad posterior sclerite, which is narrowed at both ends, in the epigynum. Biology. Individuals of M. gracilis are found on understorey plants in dense shady forests. Hodge (1987a, 1987b) studied the relationship between habitat quality and residence time on the web. Kaston (1948) reported that adult males appear from late June to early August, mature females from late June to early October. Dugdale (1969) described the web as being about 17 cm in diameter and having 44 radii and about the same number of sticky spirals. Bukowski and Christenson (1997) investigated the natural history of the species.

Micrathena mitrata (Hentz) White Micrathena Figs. 307–313; Map 35

Epeira mitrata Hentz, 1850:22, fig. 11 (pl. 3). Acrosoma mitrata: Emerton 1885:327, fig. 9 (pl. 38). Micrathena mitrata: F.O. Pickard-Cambridge 1904:538; Kaston 1948:220, figs. 694, 695 (pl.33); Levi 1978:428, figs. 28–40. Male. Total length 3.49, 3.50 mm; carapace 1.40, 1.58 mm long, 1.20, 1.25 mm wide (2 specimens measured). Carapace brown, with 3 pairs of dimples (Fig. 308). Legs brown; coxa I with minute hook. Abdomen approximately rectangular in outline, off-white, with brownish markings (Fig. 308). Palpus with 1 dorsal macroseta; median apophysis large, with blunt curved tip (Fig. 313); embolus slender, with broad undulating lamella (Fig. 313); paracymbium short, thick (Fig. 312). Female. Total length 5.03 ± 0.48 mm; carapace 1.83 ± 0.21 mm long, 1.44 ± 0.11 mm wide (8 specimens measured). Carapace brown, with pale lateral mar148

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Figs. 307–313. Micrathena mitrata. 307, female, dorsal view; 308, male, dorsal view; 309, 310, epigynum; 309, ventral view; 310, posterior view; 311, spermathecae; 312, 313, palpus of male: 312, retrolateral view; 313, mesal view. e, embolus; ma, median apophysis; pc, paracymbium.

gins, and with 3 pairs of dimples (Fig. 307). Legs brown. Abdomen off-white or pale yellow, with black median markings, and with 2 pairs of small spines posteriorly (Fig. 307). Epigynum with pointed median projection (Fig. 309); posterior sclerite flask-shaped (Fig. 310); spermathecae large, ovoid, oblique, indented anteriorly (Fig. 311). Range. Wisconsin to Maine, south to Panama. 149

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Map 35. Collection localities of Micrathena mitrata.

Comments. Specimens of M. mitrata are distinguished from those of other species in the genus by the 3 pairs of carapace dimples, by the presence of 2 pairs of abdominal spines in females, by the large, curved median apophysis, by the embolus lamella, by the short thick paracymbium, and by the flask-shaped posterior sclerite on the epigynum. Biology. Individuals of M. mitrata are found in understorey shrubs in shady forests.

Genus Gea C.L. Koch Members of the genus Gea build vertical webs in open spaces among shrubs or low herbs. Diurnal in activity, they may be found at the hub of the web with legs I and II spread forward and III and IV backward. They are less conspicuous than the representatives of Argiope, and the males and females are rather small and nearly alike in size. The web usually lacks a stabilimentum. 150

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Description. Total length 5.0–9.0 mm. Carapace yellowish brown. Sternum yellowish, with pale median and radiating lines. Legs yellowish brown, with dark rings; coxa I of male with ventral cusp, without hook. Abdomen often shieldshaped, often with pair of small humps anterolaterally, pale with dark area posteriorly or dark with white areas (Figs. 314, 315); venter pale with small irregular dark spots or dark with 2 pairs of large white spots (Fig. 317). Palpus of male (Figs. 321, 322) with sclerites rather compact; tegulum large, rather flat, covering much of retrolateral side of bulb; embolus long, hairlike, arising distally on bulb and lying within curve of conductor, with 2 sclerites interposed between its base and the tegulum; conductor broad, curved; median apophysis small, hooked, situated basal to conductor; paracymbium small, fingerlike, situated at base of cymbium. Epigynum usually weakly sclerotized, usually with broad rim posteriorly (Fig. 318); median septum visible only in posterior view, broad, with paired swellings near midlength (Fig. 319); spermathecae small, round, nearly touching (Fig. 320). Comments. Members of the genus Gea can be distinguished from those of Argiope by the nearly equal spacing of the eyes in the posterior row, by the more compact genital bulb of males, and by the posterior rim of the epigynum in females. The genus is small, probably comprising less than 10 world species (Levi 1968, 1983). A single species, G. heptagon (Hentz), is represented in North America and in Canada.

Gea heptagon (Hentz) Figs. 314–322; Map 36

Epeira heptagon Hentz, 1850:2, figs. 5, 6 (pl. 3). Ebaea praecincta L. Koch, 1872a:130, figs. 2, 3 (pl. 10). Gea heptagon: Keyserling 1892:76, fig. 58 (pl. 3); Levi 1968:324, figs.1–24; 1983:322, figs. 334, 335, 338–344. Gea praedicta O. Pickard-Cambridge, 1898:267, fig. 11 (pl. 37). Gea heptagon var. nigra Petrunkevitch, 1930:245, figs. 97–100. Male. Total length 3.97 (2.60–5.31) mm; carapace 2.09 (1.70–2.66) mm long, 1.78 (1.50–2.30) mm wide (6 specimens measured). Carapace yellowish. Abdomen pale with distinct black spot posteriorly (Fig. 316). Palpus with bulbal sclerites compact; embolus broad at base, tapering to hairlike thickness (Fig. 322); conductor large, gently curved around apical end of bulb (Fig. 321). Female. Total length 4.07, 4.50, 5.98 mm; carapace 1.40, 1.66, 2.49 mm long, 1.45, 1.80, 1.88 mm wide (3 specimens measured). Abdomen white, with black angular spot posteriorly (Fig. 314); venter with paired white spots (Fig. 317). Epigynum with prominent transverse rim posteriorly (Fig. 318) and with slender posterior sclerite (Fig. 319); spermathecae small, round (Fig. 320). 151

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Figs. 314–322. Gea heptagon. 314, 315, female, dorsal views; 316, male, dorsal view; 317, abdomen of female, ventral view; 318, 319, epigynum: 318, ventral view; 319, posterior view; 320, spermathecae; 321, 322, palpus of male: 321, ventral view; 322, retrolateral view. con, conductor; e, embolus; pc, paracymbium; teg, tegulum.

Range. California and Michigan, south to Panama and the West Indies; South Pacific Islands, Australia. Comments. Specimens of G. heptagon are distinguished from those of other species in the genus by the apical position of the embolus and the gently curved conductor in males, and by the raised posterior rim of the epigynum in females.

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Map 36. Collection localities of Gea heptagon.

Biology. The web is vertical and is placed in openings between low herbs. There is no stabilimentum. Sabath (1969) claimed that this spider has the ability to change color.

Genus Argiope Audouin Members of the genus Argiope are often strikingly colored orb weavers of open fields, meadows, and forest clearings. It is claimed that the color patterns are not species specific but may repeat themselves in remotely related species (Levi 1983). Diurnal hunters, these spiders take up the prey-ready stance at the hub of their nearly vertical webs on bright sunny days. No retreat is made. A stabilimentum of dense white silk is common. Females tend to be large and thick bodied, males tiny. Description. Total length approximately 5.0 mm (males), 18.0 mm (females). Carapace rather low, broadly rounded at lateral margins, abruptly narrowed anteriorly to approximately one-half its maximum width, often covered with appressed shiny setae. Anterior lateral eyes minute, often not visible in dorsal view; posterior row of eyes strongly procurved (Figs. 324, 330); posterior median eyes closer together than to posterior lateral eyes. Legs long, rather slender; legs I and II nearly equal in length; coxa I of male with ventral cusp, with-

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out hook. Abdomen shield-shaped or somewhat elongate and dorsally flattened, often brightly patterned (Figs. 323, 329). Palpus of male with genital bulb protruding conspicuously from alveolus (Figs. 325, 335); tegulum large, rounded in outline, situated on retrolateral side of bulb; median apophysis long, flat, bladelike, often straight, sometimes coiled, with tip lying on conductor; conductor long, scooplike or paddlelike, expanded distally; terminal apophysis lacking; paracymbium small, fingerlike, situated at base of cymbium. Epigynum (Figs. 326, 331) with raised anterior margin, with large lateral depressions, usually with strong raised median septum, which is continuous with anterior rim; scape usually present; spermathecae kidney-shaped or pear-shaped (Figs. 328, 332). Comments. Members of the genus Argiope are distinguished from those of other genera of Araneidae by the strongly procurved posterior row of eyes, and by the posterior median eyes being closer to each other than to the posterior lateral eyes. The genus was revised for the Americas by Levi (1968) and for the western Pacific region, including Australia and southeast Asia, by Levi (1983). Approximately 70 species have been recorded for the world, six for North America, and two for Canada.

Key to species of Argiope 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2(1).

Palpal sclerites elongate, extending far beyond margin of cymbium (Figs. 325, 327) . . . . . . . . . . . . . . . . . . . aurantia (Lucas) (p. 155)

2'.

Palpal sclerites not elongate, not extending far beyond margin of cymbium (Figs. 334, 335). . . . . . . . . . trifasciata (Forskål) (p. 157)

3(1').

Abdomen with pattern of large black and yellow areas (Fig. 323) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . aurantia (Lucas) (p. 155)

3'.

Abdomen with pattern of transverse white, yellow, or black lines (Fig. 329) . . . . . . . . . . . . . . . . . . . . . . trifasciata (Forskål) (p. 157)

Clé des espèces d’Argiope 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2(1).

Sclérites du palpe allongés, se prolongeant bien au-delà du cymbium (figs. 325, 327) . . . . . . . . . . . . . . . . . . . aurantia (Lucas) (p. 155)

2'.

Sclérites du palpe plus courts, ne se prolongeant pas au-delà du cymbium (figs. 334, 335) . . . . . . . . . . . . trifasciata (Forskål) (p. 157)

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3(1').

Surface dorsale de l’abdomen ornée de grandes zones jaunes et noires (fig. 323) . . . . . . . . . . . . . . . . . . . . . . . . . aurantia (Lucas) (p. 155)

3'.

Surface dorsale de l’abdomen ornée de traits transverses blancs, jaunes, et noirs (fig. 329) . . . . . . . . . trifasciata (Forskål) (p. 157)

Argiope aurantia (Lucas) Yellow Garden Argiope Figs. 323–328; Map 37

Argyope aurantia Lucas, 1833:86, fig. 1, 1a (pl. 5). Argiope aurantia: Simon 1895:765; Kaston 1948:221, figs. 696 (pl. 33), 717–721 (pl. 34), 2029, 2030 (pl. 117), 2031–2033 (pl. 118); Levi 1968:338, figs. 43–57. Epeira cophinaria Walckenaer, 1841:109. Epeira ambitoria Walckenaer, 1841:112. Epeira riparia Hentz, 1847:468, fig. 5 (pl. 30). Epeira sutrix Hentz, 1847:478, fig. 23 (pl. 31). Argiope riparia var. multiconcha Treat, 1887:1122.

Map 37. Collection localities of Argiope aurantia.

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Figs. 323–328. Argiope aurantia. 323, abdomen of female, dorsal view; 324, male, dorsal view; 325, 327, palpus of male: 325, retrolateral view; 327, mesal view; 326, epigynum; 328, spermathecae. con, conductor; e, embolus; ma, median apophysis; spt, spermatheca; teg, tegulum.

Argiope personata O. Pickard-Cambridge, 1893:110, fig. 14 (pl. 14). Argiope godmani O. Pickard-Cambridge, 1898:236, fig. 8 (pl. 37). Male. Total length 5.77 (5.48–6.68) mm; carapace 2.80 (2.33–2.90) mm long, 1.97 (1.67–2.17) mm wide (6 specimens measured). Carapace (Fig. 324) brownish, covered with white recumbent setae. Sternum black, with white median longitudinal band. Legs brownish. Abdomen black dorsally, with indistinct 156

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paired yellowish white longitudinal bands; venter black, with paired indistinct longitudinal lines. Palpus with bulbal sclerites protruding far laterally (Figs. 325, 327); embolus long, nearly straight, with tip flat and narrowed; conductor paddlelike (Fig. 327). Female. Total length 17.13 ± 1.79 mm; carapace 5.68 ± 0.61 mm long, 4.49 ± 0.54 mm wide (10 specimens measured). Carapace yellowish white, with brown markings, and with covering of silvery appressed setae. Sternum as in male. Legs I black, II–IV black, with broad reddish brown rings. Abdomen with paired lobes at anterior end, black with large conspicuous paired yellow spots (Fig. 323); venter black, margined with white, with 3 or 4 pairs of small white spots. Epigynum with prominent broad scape; scape truncate and spoonlike at tip (Fig. 326); spermathecae small, bean-shaped or kidney-shaped (Fig. 328). Range. Washington to Nova Scotia, south to Guatemala. Comments. Specimens of A. aurantia are readily distinguished from those of other species in the genus by the bright yellow and black abdomen and protruding broad epigynal scape of females, and by the paddle-shaped conductor of the male palpus. Biology. The species is annual, males being mature in July and August, females from August to October. Eggs are laid in autumn; the sac is papery and round, and is suspended among fallen leaves. The young winter in the cocoon and emerge with the onset of warm weather in spring. The web is build among goldenrod or other high herbs, in open sunny fields, meadows, or flower gardens. A zig-zag stabilimentum is present. Horton (1979) suggested that the web may be attractive in some way to adult males of the northern buckmoth. Anderson and Tillinghast (1980) analyzed the water-soluble components of the sticky spiral, and inferred that the high levels of these components in A. aurantia may act as a contact sex pheromone. Gorham (1968) discussed envenomation by A. aurantia, and Eisner and Nowicki (1983) experimented on the function of the stabilimentum.

Argiope trifasciata (Forskål) Banded Argiope Figs. 329–335; Map 38

Aranea trifasciata Forskål, 1775:86. Aranea fastuosa Olivier, 1789:202. Argyope aurelia Audouin, 1826:124, fig. 5 (pl. 2). Epeira webii Lucas, 1838:38, fig. 5 (pl. 6). Epeira argyraspides Walckenaer, 1841:110. Epeira flavipes Nicolet, 1849:493. Argyope avara Thorell, 1859:299. 157

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Figs. 329–335. Argiope trifasciata. 329, abdomen of female, dorsal view; 330, male, dorsal view; 331, 333, epigynum: 331, ventral view; 333, posterior view; 332, spermathecae; 334, 335, palpus of male: 334, mesal view; 335, ventral view. con, conductor; e, embolus; ma, median apophysis; s, scape; spt, spermatheca; teg, tegulum.

Argiope plana Thorell, 1867:181. Argiope trifasciata: Thorell, 1873:519; Kaston 1948:222, figs. 697–699 (pl. 33), 722, 723 (pl. 34), 2034, 2035 (pl. 119); Levi 1968: 340, figs. 58–72, 74–91, plate 1; 1983:286, figs. 112–119. Brachygea platicephala di Caporiacco, 1947:24. Argiope pradhani Sinha, 1952:76, fig. 2. Male. Total length 5.06 ± 0.57 mm; carapace 2.25 ± 0.21 mm long, 1.88 ± 0.18 mm wide (10 specimens measured). Carapace whitish or yellowish. Sternum yellowish brown. Legs yellow to yellowish brown. Abdomen white, with indis158

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Map 38. Collection localities of Argiope trifasciata.

tinct black markings (Fig. 330); venter with paired white longitudinal lines bordered laterally by black lines. Palpus with bulbal sclerites compact, not protruding far beyond cymbium (Figs. 334, 335); embolus and conductor lying in flat circle (Figs. 334, 335). Female. Total length 13.29 ± 1.24 mm; 4.43 ± 0.44 mm long, 1.88 ± 0.41 mm wide (10 specimens measured). Carapace covered with silvery appressed setae. Sternum black, with white median longitudinal band and with paired white spots laterally. Legs dark yellowish to brown, with darker rings. Abdomen ovoid, rounded anteriorly, somewhat pointed posteriorly, white with numerous thin transverse black lines (Fig. 329); venter black, with pair of longitudinal white lines and 3 or 4 pairs of white spots. Epigynum with broad, parallel-sided median septum (Figs. 331, 333); septum expanded posteriorly (Fig. 331); spermathecae small, approximately bean-shaped (Fig. 332). Range. Southern British Columbia to Nova Scotia, south to Chile; Mediterranean region, Africa, Sri Lanka, Australia, South Pacific Islands, China. Comments. Specimens of A. trifasciata are distinguished from those of other species of Argiope by the whitish ovoid abdomen traversed by numerous thin black lines, by the flat embolus, and by the posterior expansion of the median septum. 159

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Biology. Males of A. trifasciata are mature from late July to mid-September, and females are mature from late August to the time of autumn frosts. Eggs are deposited in a brown hemispherical cocoon in autumn, and attached to herbs or to the lower parts of shrubs. The web is made among weeds and tall grass in fields and meadows. Horton (1979) thought the web to be attractive in some way to adult males of the northern buckmoth. Olive (1982) reported finding aggregations of A. trifasciata in relation to high prey density. McNett and Rypstra (1997) supplemented prey in a field population of A. trifasciata; they found that extra prey seemed to result in a decrease in moving from one web site to another.

Genus Cyclosa Menge Spiders of the genus Cyclosa possess a strongly narrowed carapace in front and a bulging abdomen that extends posteriorly beyond the level of the spinnerets in an angular tubercle. There may be additional humps anterolaterally or beside the posterior tubercle. The body is drably colored with patterns of black, gray, or green on off-white or silvery backgrounds. The web, which is occupied during the day and left vacant at night, has relatively few frame threads. A stabilimentum composed of the bodies of dead prey and other debris, and/or the female’s egg sacs, passes vertically through the hub, and the spider often sits in the midst of this structure, or at one end of it, thus achieving a remarkable degree of camouflage. Description. Total length of males 2.1–4.9 mm, of females 3.3–9.0 mm. Carapace brown, covered with fine setae, strongly narrowed anteriorly (Figs. 336, 337, 347, 348). Eyes small; anterior median eyes somewhat larger than other eyes; posterior median eyes essentially touching. Legs short, pale brown or gray, sometimes with dark rings; coxa I of males with hook, and femur II with groove; tibia II of males only slightly thickened, with few more macrosetae than tibia I (Figs. 337, 348). Abdomen bulging anteriorly, with large angular tubercle posteriorly, sometimes with additional smaller humps, patterned with gray or black, rarely green or silvery; venter with broad black band; band extending around spinnerets and interrupted by transverse white band at middle (Fig. 340). Male palpal patella with single dorsal macroseta; cymbium short, slender; genital bulb large, conspicuously expanded ventrally (Figs. 346, 354); tegulum small, situated at base of bulb; median apophysis stout, well sclerotized, hooked at tip, directed ventrally (Figs. 346, 354); embolus long, threadlike, with base concealed by cymbium, extending diagonally across surface of bulb; conductor large, supporting tip of embolus; terminal apophysis small, pointed. Epigynum with slender, often weakly sclerotized scape (Figs. 342, 350); scape arising at anterior margin of epigynum and extending to posterior margin; posterior sclerite broad, abruptly tapered dorsally (Figs. 343, 351); spermathecae large, rounded or kidneyshaped (Figs. 344, 352).

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Comments. Representatives of the genus Cyclosa are distinguished from those of other araneid genera by the prominent angular abdominal tubercle, which is often accompanied by additional humps, by the ventral black band that passes around the spinnerets and is interrupted at the middle by a transverse white band, and by the stout, hooked, ventrally directed paramedian apophysis. Catalogues record somewhat more than 100 world species of Cyclosa distributed widely on most continents. Levi (1977a) revised the five American species north of Mexico, two of which are represented in Canada.

Key to species of Cyclosa 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2(1).

Coxa IV with pair of small macrosetae ventrally (Fig. 341). Paramedian apophysis with tip broadly folded (Figs. 345, 346) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . conica (Pallas) (p. 162)

2'.

Coxa IV without macrosetae. Paramedian apophysis with tip not broadly folded (Figs. 353, 354) . . turbinata (Walckenaer) (p. 164)

3(1').

Scape of epigynum tapered toward posterior end (Fig. 342) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . conica (Pallas) (p. 162)

3'.

Scape of epigynum widest at midlength (Fig. 350) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . turbinata (Walckenaer) (p. 164)

Clé des espèces de Cyclosa 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2(1).

Coxa IV portant une paire de petites soies articulées sur la face ventrale (fig. 341). Apex de l’apophyse paramédiane replié sur lui-même (figs. 345, 346) . . . . . . . . . . . . . . . . . . . . . . conica (Pallas) (p. 162)

2'.

Coxa IV sans soies articulées. Apex de l’apophyse paramédiane non replié sur lui-même (figs. 353, 354) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . turbinata (Walckenaer) (p. 164)

3(1').

Scape de l’épigyne rétrécissant de la base vers l’extrémité (fig. 342) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . conica (Pallas) (p. 162)

3'.

Scape de l’épigyne élargissant dans la partie médiane (fig. 350) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . turbinata (Walckenaer) (p. 164)

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Cyclosa conica (Pallas) Figs. 336–346; Map 39

Aranea conica Pallas, 1772:48, fig. 16 (pl. 1). Epeira canadensis Blackwall, 1846:81. Cyclosa conica: Emerton 1885:321, figs. 3 (pl. 34), 11 (pl. 38). Wiehle 1931:18, figs. 8, 17–21. Kaston 1948:236, figs. 711–713 (pl. 33), 2037 (pl. 120); Levi 1977a:78, plate 1, figs. 1–19; 1999:320, figs. 42–48; Roberts 1985:222, fig. 100b. Male. Total length 3.99 ± 0.36 mm; carapace 2.01 ± 0.07 mm long, 1.55 ± 0.08 mm wide (10 specimens measured). Carapace brownish, somewhat paler anteriorly, strongly narrowed toward front (Fig. 337). Legs pale, with indistinct dark rings at tips of most segments; tibia II somewhat stouter and with somewhat longer macrosetae than tibia I (Figs. 337, 339); coxa IV with 1 or 2 small macrosetae ventrally (Fig. 341). Abdomen with indistinct brownish pattern mesally (Fig. 337). Palpus with small tegulum, stout paramedian apophysis, and long threadlike embolus; paramedian apophysis with tip broadly folded (Figs. 345, 346).

Map 39. Collection localities of Cyclosa conica.

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Figs. 336–346. Cyclosa conica. 336, 338, female: 336, dorsal view; 338, lateral view; 337, 339, male: 337, dorsal view; 339, lateral view; 340, abdomen of female, ventral view; 341, coxae IV, ventral view; 342, 343, epigynum: 342, ventral view; 343, posterior view; 344, spermathecae; 345, 346, palpus of male: 345, ventral view; 346, mesal view. e, embolus; ls, lateral sclerite; ma, median apophysis; pp, posterior plate; s, scape; spt, spermatheca.

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Female. Total length 5.11 ± 0.70 mm; carapace 1.91 ± 0.15 mm long, 1.46 ± 0.12 mm wide (10 specimens measured). Coloration as in male but abdominal pattern more distinct (Figs. 336, 340). Epigynum with posteriorly tapering scape, and with curved lateral sclerites (Fig. 342); posterior plate broad, tapered dorsally to slender point (Fig. 343); spermathecae rounded (Fig. 344). Range. Alaska to Newfoundland, south to Baja California, Guatemala, and Virginia; Europe and Asia. Comments. Specimens of C. conica are distinguished from those of other species in the genus by the folded paramedian apophysis and one or two ventral macrosetae on coxa IV, and by the posteriorly tapered median septum. Biology. Individuals of C. conica build webs in the understory of coniferous or mixed forests. The orb web has 40–50 radii, and is commonly situated 2 m or more above ground. If disturbed, the spider may set the web in rapid vibration. A row of dead prey and other debris may be built along a vertical radius. Kaston (1948) states that the spider winters in the penultimate or antepenultimate instar, and is mature from mid-May to summer. Egg sacs are fastened to dead twigs or under leaves near the web. Wiehle (1931) stated that May is the month when most individuals are mature in Germany, and that the young begin to appear at the end of June. The sac is round and golden yellow, and may contain 50–60 eggs.

Cyclosa turbinata (Walckenaer) Cyclosa Orbweaver Figs. 347–354; Map 40

Epeira turbinata Walckenaer, 1841:140. Epeira caudata Hentz, 1850:23, fig. 14 (pl. 3). Singa vanbruysselii Becker, 1879:78, figs. 4–6 (pl. 1). Cyclosa index O. Pickard-Cambridge, 1889:51, fig. 6 (pl. 6). Cyclosa culta O. Pickard-Cambridge, 1893:112, fig. 12 (pl. 14). Cyclosa turbinata: McCook 1894:224, figs. 5, 6 (pl. 17); Kaston 1948:237, fig. 710 (pl.33); Levi 1977a:80, plate 2, figs. 20, 38–50; 1999:356, figs. 314–321. Cyclosa nanna Ivie and Barrows, 1935:18, figs. 52, 53. Male. Total length 2.84 ± 0.31 mm; carapace 1.52 ± 0.13 mm long, 1.26 ± 0.31 mm wide (8 specimens measured). Carapace brownish, strongly narrowed toward front (Fig. 348). Legs pale, without distinct rings; tibia II with macrosetae stouter and more numerous than tibia I (Fig. 348); coxa IV lacking ventral macrosetae. Abdomen pale, with paired off-white spots anteriorly and with dark median pattern posteriorly (Fig. 348). Palpus with small tegulum, stout paramedian apophysis, and long threadlike embolus; paramedian apophysis pointed and somewhat hooked at tip, with small pointed spur (Figs. 353, 354).

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Figs. 347–354. Cyclosa turbinata. 347, female, dorsal view; 348, male, dorsal view; 349, abdomen of female, ventral view; 350, 351, epigynum: 350, ventral view; 351, posterior view; 352, spermathecae; 353, 354, palpus of male: 353, mesal view; 354, ventral view. pma, paramedian apophysis; spt, spermatheca.

Female. Total length 4.74 (4.15–5.64) mm; carapace 1.65 (1.41–1.85) mm long, 1.17 (1.10–1.33) mm wide (6 specimens measured). Coloration as in male but much more distinct (Figs. 347, 349). Epigynum with paired deep openings and broad ovoid scape (Fig. 350); posterior sclerite broad, tapered dorsally to slender piece (Fig. 351); spermathecae kidney-shaped (Fig. 352).

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Map 40. Collection localities of Cyclosa turbinata.

Range. Washington to Michigan and New York, south to Baja California, Panama, Caribbean islands, and the Galapagos Islands. Comments. Specimens of C. turbinata are distinguished from those of other species of Cyclosa by the pointed hooked paramedian apophysis, which has a small pointed spur at its base, and by the broad ovoid scape. Biology. Individuals of C. turbinata have been collected in open habitats such as abandoned fields, gardens, lawns, and meadows and salt marshes, and also in oak forests. The web has a vertical stabilimentum in which the female incorporates its egg sacs. Males have been taken from May to August, females from May to September.

Genus Neoscona Simon Members of the genus Neoscona are commonly collected by sweep nets in meadows and weedy fields, but may be found on shrubs and fences as well. The web is nearly vertical, and may be 40–60 cm in diameter. The hub is open except for a few cross threads. There may be 18–20 radii and 30 or more sticky spirals. The spider hunts on the web at night, and remains in a retreat, usually within a curled leaf, near the web during daylight hours. Adults appear in late June or in

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July, and the eggs are laid in September. The sacs are somewhat flattened, covered with loose silk, and suspended within the retreat. Up to a thousand eggs have been counted in a single sac (Kaston 1948). Description. Total length 4.2–19.7 mm. Carapace yellow to brown, with pattern of dark streaks laterally and radiating from dorsal groove; dorsal groove longitudinal. Legs yellowish, with femora, patellae, and tibiae darker on distal half; males with spur on coxa I and with cluster of stout macrosetae prolaterally on tibia II. Abdomen ovoid, elongate, or triangular, sometimes with paired anterolateral humps (Figs. 355, 363, 372), with pattern of paired dark oblique marks on gray or yellowish background, or with paired longitudinal stripes and spots on greenish background, or with uneven pale median band on dark background; venter black, with white longitudinal line or series of spots laterally. Palpus of male (Figs. 358, 361, 362, 370, 371, 374, 376, 377) with 2 long slender macrosetae on patella; cymbium large, covering much of genital bulb; tegulum large, convex; median apophysis, embolus, conductor, and terminal apophysis small, compact, restricted to distal third of bulb, partly concealed by cymbium; median apophysis elongate, with spur at base or near middle; embolus tube-shaped to conical, with distinct lamella; conductor fingerlike; terminal apophysis thin, flaplike, sometimes minute. Epigynum (Figs. 356, 357, 364, 365, 373, 375) with prominent spoon-shaped or tongue-shaped scape; copulatory openings situated on dorsal surface of scape; spermathecae small to large, elliptical, touching or nearly touching, situated within base of scape (Figs. 360, 368). Comments. Members of the genus Neoscona are distinguished from those of other araneid genera by the small compact cluster formed by the embolus, median apophysis, conductor, and terminal apophysis, by the broad spoon-shaped or tongue-shaped scape, and by the abdominal patterns. Representatives of few other araneid genera share the longitudinal dorsal groove found in representatives of Neoscona. Berman and Levi (1971) treated nine species in America north of Mexico. An unknown number of other species are represented in Europe, Africa, Asia, or South America. Three species are represented in Canada.

Key to species of Neoscona 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2(1).

Coxa IV with small pointed spur. Abdomen with dark median longitudinal band bordered by white lines and by series of black spots (Fig. 355) . . . . . . . . . . . . . . . . . . . . . . . pratensis (Hentz) (p. 169)

2'.

Coxa IV without spur. Abdomen with pattern differing from above ................................................... 3

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3(2').

Terminal apophysis approximately parallel at sides, fluted at tip (Figs. 369, 370). Conductor almost straight (lateral view, Fig. 369) . . . . . . . . . . . . . . . . . . . . . . . . . . . arabesca (Walckenaer) (p. 171)

3'.

Terminal apophysis tapered and flattened toward tip (Fig. 377). Conductor S-shaped (lateral view, Fig. 376) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . crucifera (Lucas) (p. 173)

4(1').

Abdominal pattern with dark median longitudinal band bordered by white lines and series of black spots (Fig. 355) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pratensis (Hentz) (p. 169)

4'.

Abdominal pattern otherwise . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

5(4').

Scape with small lateral bulges (Fig. 364) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . arabesca (Walckenaer) (p. 171)

5'.

Scape with more prominent lateral bulges (Fig. 373) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . crucifera (Lucas) (p. 173)

Clé des espèces de Neoscona 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2(1).

Coxa IV munie d’un petit éperon pointu. Abdomen orné d’une bande médiane longitudinale sombre bordée par des traits blancs et par une série de taches noires (fig. 355) . . . . . . . pratensis (Hentz) (p. 169)

2'.

Coxa IV dépourvue d’éperon. Motif de la surface de l’abdomen différent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3(2').

Bordures de l’apophyse terminale presque parallèles, apex de l’apophyse affutée (figs. 369, 370). Conducteur presque droit (vue latérale, fig. 369) . . . . . . . . . . . . . arabesca (Walckenaer) (p. 171)

3'.

Bordures de l’apophyse convergentes, apex plutôt applati (fig. 377). Conducteur en forme de S (en vue latérale) (fig. 376) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . crucifera (Lucas) (p. 173)

4(1').

Abdomen orné d’une bande médiane longitudinale sombre bordée de traits blancs et d’une série de taches noires (fig. 355) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pratensis (Hentz) (p. 169)

4'.

Motifs de la surface de l’abdomen différent . . . . . . . . . . . . . . . . . . 5

5(4').

Scape arborant des petits renflements latéraux (fig. 364) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . arabesca (Walckenaer (p. 171)

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Scape arborant des renflements latéraux plus marqués (fig. 373) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . crucifera (Lucas) (p. 173)

Neoscona pratensis (Hentz) Figs. 355–362; Map 41

Epeira pratensis Hentz, 1847:475, fig. 11 (pl. 31); Emerton 1885:310, figs. 15 (pl. 33), 9 (pl. 36). Neoscona pratensis: Comstock 1913:502, fig. 537; Kaston 1948:247, fig. 774 (pl. 36); Berman and Levi 1971:494, plate 1, figs. 101–110, 134. Male. Total length 7.00 mm; carapace 3.70 mm long, 3.20 mm wide (1 specimen measured). Carapace yellowish. Tibia II with 3 rows of stout macrosetae; coxa IV with small pointed spur. Abdomen elongate, with dark median longitudinal band bordered by white lines and series of black spots. Conductor of palpus bulbous at tip (Fig. 362); terminal apophysis tapered. Female. Total length 9.50 mm; carapace 3.60 mm long, 2.80 mm wide (1 specimen measured). Coloration as in male (Fig. 355). Scape with distinct paired lateral bulges near base, tongue-shaped distally (Fig. 356); spermathecae small, elliptical, nearly touching (Fig. 360).

Map 41. Collection localities of Neoscona pratensis.

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Figs. 355–362. Neoscona pratensis. 355, abdomen of female, dorsal view; 356, 357, 359, epigynum: 356, ventral view; 357, lateral view; 359, posterior view; 358, 361, 362, palpus of male: 358, mesal view; 361, retrolateral view; 362, mesal view, partly expanded; 360, spermathecae. con, conductor; e, embolus; ma, median apophysis; s, scape; spt, spermatheca.

Range. Northern British Columbia to southern Ontario and Massachusetts, south to Kansas, Louisiana, and Florida.

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Comments. Specimens of N. pratensis are distinguished from those of other species in the genus by the elongate abdomen, and by the distinctive pattern on the abdominal dorsum. Biology. Specimens have been collected in salt marshes, swamps, and less often in abandoned fields. Mature individuals of both sexes appear in late July and August (Kaston 1948).

Neoscona arabesca (Walckenaer) Arabesque Orbweaver Figs. 363–371; Map 42

Epeira arabesca Walckenaer, 1841:74. Epeira trivittata Keyserling, 1864:95, figs. 6–9 (pl. 5); Emerton 1885:311, figs. 16 (pl. 33), 2, 3, 5, 8 (pl. 36). Epeira singularis Banks, 1898:252, fig. 4 (pl. 15). Treated as probable junior synonym by Berman and Levi (1971:474). Neoscona arabesca: F.O. Pickard-Cambridge 1904:472, figs. 13, 14 (pl. 44); Kaston 1948:245, figs. 750 (pl. 35), 771–773 (pl. 36), 775 (pl. 37); Berman and

Map 42. Collection localities of Neoscona arabesca.

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Figs. 363–371. Neoscona arabesca. 363, abdomen of female, dorsal view; 364, 365, 367, epigynum: 364, ventral view; 365, lateral view; 367, posterior view; 366, 369–371, palpus of male: 366, 371, retrolateral views; 369, 370, mesal views; 368, spermathecae. con, conductor; e, embolus; ma, median apophysis; spt, spermatheca; term, terminal apophysis.

Levi 1971: 474, plate 1, figs. 1–3, 5, 6, 8, 10, 14–42, 125, 126. Levi 1992:230, figs. 14–17. Neoscona minima F.O. Pickard-Cambridge, 1904:471, figs. 11, 12 (pl. 44); Kaston 1948:245, figs. 751 (pl. 35), 776 (pl. 37). Male. Total length 5.41 ± 0.55 mm; carapace 2.82 ± 0.34 mm long, 2.43 ± 0.27 mm wide (10 specimens measured). Carapace yellowish. Legs yellowish, with femora, patellae, and tibiae darker in distal half; tibia II usually curved, with uneven row or rows of short stout macrosetae; coxa IV without spur. Abdomen broadly ovoid, with dorsal pattern of paired oblique dark streaks on paler back172

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ground (Fig. 363). Conductor of palpus bulbous at tip (Fig. 369); terminal apophysis fluted at tip (Figs. 369–371). Female. Total length 6.25 ± 0.66 mm; carapace 2.49 ± 0.29 mm long, 2.23 ± 0.23 mm wide (10 specimens measured). Coloration essentially as in male. Legs II and IV without sexual modifications. Epigynal scape somewhat narrowed near middle, with small lateral bulges, tongue-shaped at tip (Figs. 364, 365, 367); spermathecae small, elliptical, nearly touching (Fig. 368). Range. British Columbia to Nova Scotia, south to California, Arizona, Florida, Mexico, Central America, and the West Indies. Comments. Specimens of N. arabesca are distinguished from those of other species in the genus by their small size, by the fluted terminal apophysis in males, and usually by the paired oblique streaks on the abdominal dorsum. Biology. Specimens of N. arabesca are often taken in large numbers by sweep net in tall weeds and grass during late summer. According to Kaston (1948), the web is nearly vertical and has about 20 radii. The spider may remain at the hub in day time as well as at night, but more often builds a retreat near the web and rests there during the day. Males mature in June and July, females in July and August.

Neoscona crucifera (Lucas) Figs. 372–377; Map 43

Epeira crucifera Lucas, 1839:42, fig. 3 (pl. 6). Epeira hentzii Keyserling, 1864:97, figs. 10, 11 (pl. 5). Epeira domiciliorum: Emerton 1885:312, figs. 17 (pl. 33), 1, 4 (pl. 36). Neoscona arkansa Chamberlin and Ivie, 1942:77, figs. 217, 218. Neoscona nebraskensis Chamberlin and Ivie, 1942:77, figs. 219, 220. Neoscona benjamina: Kaston 1948:246, figs. 752 (pl. 35), 777, 778 (pl. 37). Neoscona hentzii: Berman and Levi 1971:478, figs. 51–58, 128. Neoscona crucifera: Grasshoff 1983:225; 1986:62, figs. 79–84; Schmidt 1990:422. Male. Total length 9.19, 12.11 mm; carapace 4.84, 5.90 mm long, 4.50, 4.68 mm wide (2 specimens measured). Carapace yellowish. Legs yellowish; tibia II swollen prolaterally near base, with 2 uneven rows of short stout macrosetae; coxa IV without spur. Abdomen broadly ovoid, with dorsal pattern indistinct (Fig. 372) and sometimes absent. Conductor of palpus S-shaped (Figs. 374, 376); terminal apophysis tapered, not fluted at tip (Figs. 374, 376, 377). Female. Total length 13.58 ± 2.71 mm; carapace 5.56 ± 0.57 mm long, 4.72 ± 0.28 mm wide (10 specimens measured). Coloration essentially as in male (Fig. 372). Legs lacking sexual modifications. Epigynum with long spoon-shaped 173

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Figs. 372–377. Neoscona crucifera. 372, abdomen of female, dorsal view; 373, 375, epigynum: 373, ventral view; 375, lateral view; 374, 376, 377, palpus of male: 374, mesal view; 376, retrolateral view; 377, mesal view of tip of genital bulb. con, conductor; e, embolus; ma, median apophysis; term, terminal apophysis.

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Map 43. Collection localities of Neoscona crucifera.

scape; scape with 2 pairs of lateral bulges, one pair near base and the other at narrowed part of scape (Figs. 373, 375). Range. Wisconsin and southernmost Ontario to Massachusetts, south to Arizona, central Mexico, and Florida; Canary Islands, Madeira, Porto Santo. Comments. Specimens of N. crucifera are distinguished from those of other species of Neoscona by the S-shaped conductor of the male, and by the 2 pairs of lateral bulges on the epigynal scape. The indistinct dorsal pattern on the abdomen is also of some diagnostic value, and mature specimens are larger than those of N. arabesca. Biology. Specimens of N. crucifera have been collected on shrubs, fences, and tall herbs. Maturity is attained in July and August, and eggs are laid in late August and September (Kaston 1948).

Genus Aculepeira Chamberlin & Ivie Members of the genus Aculepeira are found in high montane habitats such as talus slopes or alpine meadows. Both of the North American representatives are also represented in the high latitudes of the Yukon Territory, Alaska, and the Russian Far East (Levi 1977b). The webs are built between boulders where the

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spiders are difficult to detect and to collect, or between understorey shrubs and herbs in stands of spruce. Description. Total length 5.0–16.5 mm. Carapace ovoid, rather low, pale anteriorly, darker posteriorly, with silky white setae posteriorly (Figs. 378, 379, 387). Eyes small, approximately equal in size; anterior row of eyes recurved; posterior row of eyes straight or recurved. Palp-coxal lobes with tooth laterally, and palpal femur with similar tooth. Legs pale, with conspicuous dark rings; coxa I of male sometimes with hook; tibia II with stout macrosetae at tip (Fig. 378). Abdomen elongate-ovoid, broadest in anterior third, with white scalloped or broken median band (Figs. 378, 379, 387); venter dark, with median white mark (Figs. 380, 388). Palpus of male (Figs. 385, 386, 393, 394) with sclerites facing mesally; patella usually with 2 strong macrosetae; median apophysis elongate, flattened or fluted at distal end and bearing 2 slender spurs at base (Figs. 385, 393); conductor boat-shaped to disk-shaped; embolus small, concealed in ventral view; terminal apophysis long, curved, distally spear-shaped (Figs. 385, 393); paracymbium small, situated at base of cymbium. Epigynum (Figs. 381–383, 389–391) with large grooved scape; posterior sclerite angular to T-shaped (Fig. 390); spermathecae small, round, touching or nearly touching (Figs. 384, 392). Comments. Representatives of the genus Aculepeira are distinguished from those of other araneid genera (except Larinia, Eustala, and Metepeira) by the presence of a median white mark on the abdominal venter, and by the 2 slender spurs at the base of the median apophysis. They are distinguished from individuals of Metepeira spp., in which the median apophysis also has 2 slender spurs, by the elongate-ovoid abdomen. A world fauna of approximately 20 species is known (Platnick 1989). Two are represented in North America, both of these appearing in Canada.

Key to species of Aculepeira l.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2(1).

Conductor of palpus with long ridge (Fig. 385) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . packardii (Thorell) (p. 177)

2'.

Conductor of palpus without ridge (Fig. 393) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . carbonarioides (Keyserling) (p. 179)

3(1').

Scape of epigynum nearly as wide as epigynal plate (Figs. 381, 382) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . packardii (Thorell) (p. 177)

3'.

Scape of epigynum distinctly narrower than epigynal plate (Fig. 389) . . . . . . . . . . . . . . . . . . . . . . . carbonarioides (Keyserling) (p. 179)

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Clé des espèces d’Aculepeira 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2(1).

Conducteur muni d’une longue carène (fig. 385) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . packardii (Thorell) (p. 177)

2'.

Conducteur sans carène (fig. 393) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . carbonarioides (Keyserling) (p. 179)

3(1').

Scape de l’épigyne presque aussi large que la plaque de l’épigyne (figs. 381, 382) . . . . . . . . . . . . . . . . . . packardii (Thorell) (p. 177)

3'.

Scape de l’épigyne beaucoup plus étroit que la plaque de l’épigyne (fig. 389) . . . . . . . . . . . . . . . . carbonarioides (Keyserling) (p. 179)

Aculepeira packardii (Thorell) Figs. 378–386; Map 44

Epeira packardii Thorell, 1875:490. Epeira aculeata Emerton in Thorell, 1877:528, fig. 18; Emerton 1894:405, figs. 4a, 4c, 4e (pl. 1). Araneus septentrionalis Kulczy½ski, 1908:47, fig. 57. Aculepeira verae Chamberlin and Ivie, 1942:75, figs. 215, 216. Aculepeira packardi: Levi 1977b:228, plate 6, figs. 148–161, 174, 176–181; 1991:298. Male. Total length 5.85 ± 1.05 mm; carapace 2.97 ± 0.38 mm long, 2.70 ± 0.78 mm wide (9 specimens measured). Carapace brownish, darker posteriorly. Legs with indistinct dark rings. Abdomen with pale median band giving off 4 or 5 posterolaterally directed lobes (Fig. 378). Palpus with small pointed embolus and with large conductor (Figs. 385, 386); conductor with ridge extending full length of conductor (Fig. 385). Female. Total length 10.77 ± 2.19 mm; carapace 4.04 ± 0.76 mm long, 3.27 ± 0.68 mm wide (10 specimens measured). Coloration as in male, but dark rings on legs more distinct (Fig. 379). Venter of abdomen with broad white median band (Fig. 380). Epigynum with broad scape (nearly as wide as epigynal plate, Figs. 381, 382) (scape may be missing in mated specimens); posterior plate angular to T-shaped; spermathecae round, nearly touching (Fig. 384). Range. Yukon Territory to Labrador, south to Chihuahua, Mexico and to northern Pennsylvania; Russian far east, southern Siberia, and northern China.

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Figs. 378–386. Aculepeira packardii. 378, male, dorsal view; 379, female, dorsal view; 380, abdomen of female, ventral view; 381–383, epigynum: 381, 382, ventral views; 383, lateral view; 384, spermathecae; 385, 386, palpus of male: 385, mesal view; 386, ventral view. con, conductor; ma, median apophysis; teg, tegulum; term, terminal apophysis.

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Map 44. Collection localities of Aculepeira packardii.

Comments. Specimens of A. packardii are distinguished from those of other species in the genus by the ridge found on the conductor of the male palpus, by the broad scape on the epigynum, and by the lobed abdominal pattern. Biology. Levi (1977b) observed the webs of this spider in alpine meadows of western Colorado at 2500–3000 m elevation. Females were mature in August, and were seen renewing their webs each night. One web had 19 radii and 24 or 25 sticky spirals. The spider spent daylight hours in a silk-lined retreat in foliage beside the web.

Aculepeira carbonarioides (Keyserling) Figs. 387–394; Map 45

Epeira carbonaria: Emerton 1885:315, figs. 18 (pl. 33), 19 (pl. 18); 1894:405, figs. 4b, 4d (pl. 1). Not carbonaria (L. Koch). Epeira carbonarioides Keyserling, 1892:206, fig. 152 (pl. 10).

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Figs. 387–394. Aculepeira carbonarioides. 387, female, dorsal view; 388, abdomen of female, ventral view; 389–391, epigynum: 389, ventral view; 390, posterior view; 391, lateral view; 392, spermathecae; 393, 394, palpus of male: 393, mesal view; 394, ventral view. bla, basal lamella; con, conductor; e, embolus; ls, lateral sclerite; ma, median apophysis; pp, posterior plate; s, scape; teg, tegulum; term, terminal apophysis.

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Map 45. Collection localities of Aculepeira carbonarioides.

Araneus hyperboreus Kulczy½ski, 1908:45, fig. 58. Probable synonym by Levi (1977b) and by Marusik (1985). Aranea charitonovi Ermolajew, 1928:209. Regarded as probable junior synonym by Levi (1977b). Araneus vegae Holm, 1970:198, figs. 25–27, 29, 30. Aculepeira carbonarioides: Levi 1977b:230, plate 7, figs. 162–173, 182–186. Male. Total length 6.51, 8.60, 10.35 mm; carapace 3.34, 4.51, 4.90 mm long, 2.67, 4.01, 4.10 mm wide (3 specimens measured). Carapace yellowish anteriorly, much darker posteriorly and along sides (Fig. 387). Legs pale with dark rings. Abdomen dark, with white median band (Fig. 387); band broken into numerous irregular spots; venter dark, with narrow white midstripe (Fig. 388). Palpus with moderately large truncated embolus and large conductor; conductor lacking ridge (Figs. 393, 394). Female. Total length 11.54 ± 1.40 mm; carapace 3.99 ± 0.41 mm long, 3.48 ± 0.49 mm wide (10 specimens measured). Coloration as in male, but leg rings more distinct (Fig. 387). Epigynum with narrow tapered scape (Fig. 389);

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posterior sclerite shield-shaped (Fig. 390); basal lamellae minute (Fig. 390); spermathecae round or ovoid, nearly touching (Fig. 392). Range. Alaska to Quebec, south to Utah and Colorado; Scandinavia and Russia. Comments. Specimens of A. carbonarioides are distinguished from those of others in the genus by the lack of a ridge on the conductor of males, by the narrow scape, by the shield-shaped posterior plate of the epigynum, and by the broken abdominal pattern. Biology. Individuals of this species build their webs in the spaces among boulders at or near tree line. The web “forms an angle with the vertical” and the spider is found at the hub rather than in a retreat (Levi 1977b).

Genus Larinioides di Caporiacco Members of the genus Larinioides are drably colored nocturnal orb weavers. They build their webs in early evening, and remain at the hub until morning, when they usually move to a silk retreat in a nearby crevice or dead leaf. The common habitats are walls, rail fences, tree trunks, and bridges. Docks and boathouses may become festooned by their webs during summer and early autumn, when emerging aquatic insects are attracted to lights at night. The web has fewer than 20 radii, a few hub threads, and is usually vertical or nearly so. Description. Total length 4.7–12.0 mm (males), 6.5–14.0 mm (females). Carapace setose, usually brownish, broad and rather low, with distinct grooves radiating anterolaterally from dorsal groove (Figs. 402, 409). Eyes small; median eyes somewhat larger than laterals; lateral eyes situated together on small prominence; posterior row of eyes straight or somewhat recurved. Legs grayish or brownish; coxa I of male with hook; tibia II of males sometimes swollen and bearing many stout macrosetae. Abdomen round or broadly elliptical, rather flat dorsally, without anterolateral humps, with grayish or brownish pattern (Figs. 395, 402, 403, 409, 410); venter black, with paired comma-shaped or bracket-shaped white marks (Figs. 396, 411). Palpus of male (Figs. 400, 401, 407, 408, 415, 416) with 2 patellar macrosetae; tegulum large, curved around entire retrolateral surface of genital bulb; median apophysis usually projecting from mesal surface of bulb, usually bifid (Figs. 400, 407, 415); embolus short, slender, fingerlike; conductor small, flat; terminal apophysis large, pointed or blunt at tip, arched over embolus. Epigynum (Figs. 397, 404, 412) strongly sclerotized, with scape; scape fingerlike or tonguelike, rather short, smooth or somewhat wrinkled in appearance, attached at anterior epigynal margin (Figs. 397, 404, 412); posterior plate large, angular, broader than long (Figs. 398, 405, 413); spermathecae small, round or dumbbell-shaped (Figs. 399, 406, 414).

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Comments. Specimens of Larinioides spp. are distinguished from those of other araneid genera by the rounded, dorsally flattened abdomen, by the white comma-shaped or bracket-shaped marks on the abdominal venter, by the mesally projecting bifid median apophysis, and by the short fingerlike or tonguelike scape. The genus was revised by Levi (1974b), who treated six world species (as Nuctenea). Three species are represented in North America, all of these in Canada.

Key to species of Larinioides 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2(1).

Terminal apophysis narrowed distally to sharp point (Fig. 401) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cornutus (Clerck) (p. 184)

2'.

Terminal apophysis blunt (Figs. 407, 415) . . . . . . . . . . . . . . . . . . 3

3(2').

Median apophysis short, with its subdivisions approximately equal in length (Fig. 407) . . . . . . . . . . . . . . . . patagiatus (Clerck) (p. 186)

3'.

Median apophysis longer, with subdivisions unequal in length (Fig. 415) . . . . . . . . . . . . . . . . . . . . . sclopetarius (Clerck) (p. 189)

4(1').

Lateral sclerites of epigynum with ridges and grooves (Fig. 405). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . patagiatus (Clerck) (p. 186)

4'.

Lateral sclerites of epigynum smooth (Figs. 398, 413) . . . . . . . . . 5

5(4').

Base of epigynum with fold on each side of the scape (Fig. 397). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cornutus (Clerck) (p. 184)

5'.

Base of epigynum with concave edge on each side of the scape (Fig. 412) . . . . . . . . . . . . . . . . . . . . . sclopetarius (Clerck) (p. 189)

Clé des espèces de Larinioides 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2(1).

Bout de l’apophyse terminale rétrécissant en une pointe (fig. 401). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cornutus (Clerck) (p. 184)

2'.

Bout de l’apophyse terminale arrondie (figs. 407, 415) . . . . . . . . . 3

3(2').

Apophyse médiane courte, les deux parties presque de même dimension (fig. 407) . . . . . . . . . . . . . . . . . . patagiatus (Clerck) (p. 186)

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3'.

Apophyse médiane plus longue, les deux parties de taille inégale (fig. 415) . . . . . . . . . . . . . . . . . . . . . sclopetarius (Clerck) (p. 189)

4(1').

Sclérites latéraux de l’épigyne garnis de carènes et de sillons (fig. 405) . . . . . . . . . . . . . . . . . . . . . . patagiatus (Clerck) (p. 186)

4'.

Sclérites latéraux de l’épigyne lisses (figs. 398, 413) . . . . . . . . . . 5

5(4'.)

Base de l’épigyne ornée de lames de chaque côté du scape (fig. 397) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cornutus (Clerck) (p. 184)

5'.

Base de l’épigyne ornée d’une marge concave de chaque côté du scape (fig. 412) . . . . . . . . . . . . . . . . sclopetarius (Clerck) (p. 189)

Larinioides cornutus (Clerck) Figs. 395–401; Map 46

Araneus cornutus Clerck, 1758:39, fig. 11 (pl. 1); Locket and Millidge 1953:134, figs. 88a, 89b, 90c.

Map 46. Collection localities of Larinioides cornutus.

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Figs. 395–401. Larinioides cornutus. 395, abdomen of female, dorsal view; 396, abdomen of female, ventral view; 397, 398, epigynum: 397, ventral view; 398, posterior view; 399, spermathecae; 400, 401, palpus of male: 400, ventral view; 401, mesal view. e, embolus; ls, lateral sclerite; ma, median apophysis; pp, posterior plate; spt, spermatheca; teg, tegulum; term, terminal apophysis.

Aranea foliata Fourcroy, 1785:533; Wiehle 1931:86, figs. 124–127. Epeira strix Hentz, 1847:473, fig. 5 (pl. 31). Epeira vicaria Kulczy½ski, 1885:5. Epeira foliata: Kaston 1948:254, figs. 787 (pl. 37), 803 (pl. 38), 812 (pl. 39), 2043 (pl. 122). Nuctenea cornuta: Levi 1974b:306, plate 2, figs. 61, 62, 67–76, 94, 97, 98, 110, 111, 118, 119, 126. Larinioides cornutus: Roberts 1985:212, fig. 95a; Heimer and Nentwig 1991:86, fig. 192. Male. Total length 7.21 ± 0.81 mm; carapace 3.79 ± 0.38 mm long, 3.26 ± 0.37 mm wide (10 specimens measured). Carapace dark orange-red, sometimes paler at margins, thinly covered with recumbent white setae. Legs yellowish to 185

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orange, with tips of segments dark; tibia II with 2 rows of short stout macrosetae on prolateral surface. Abdomen with grayish brown heart mark, and with paired angular broken markings of the same color; venter black, with distinct white bracket-shaped marks. Palpus with large bifid median apophysis; median apophysis with parts unequal in size (Fig. 400); embolus with basal fold (Fig. 401); terminal apophysis with slender sharp point (Fig. 401). Female. Total length 9.49 ± 1.41 mm; carapace 3.89 ± 0.56 mm long, 3.38 ± 0.44 mm wide (10 specimens measured). Coloration as in male (Figs. 395, 396). Epigynum with short fingerlike scape; scape usually smooth, usually flanked by deep folds in epigynal plate (Fig. 397); posterior plate broader than long, with lateral sclerites smooth, meeting broadly at midline (Fig. 398); spermathecae round (Fig. 399). Range. Alaska to Newfoundland, south to California, Florida, and Panama; Europe, Asia. Comments. Specimens of L. cornutus are distinguished from those of other species in the genus by the fold at the base of the embolus, by the distally slender terminal apophysis, and by the broad smooth lateral sclerites of the epigynum. Biology. The webs are built on buildings, fences, bridges, or in hedges and low shrubs, and are usually vertical or nearly so. The web is built toward evening, has 15–20 radii, and there is a silk-lined retreat nearby. Both sexes are mature from early spring to late autumn, and some individuals may winter in the adult stage, along with juveniles of various sizes. Eggs are laid in spring or early summer. Mating is detailed by Wiehle (1931). Sherman (1994) investigated the relationship between foraging success and reproductive success, and Ysnel (1990) gives data on energy consumption during postembryonic development. Yu and Coddington (1990) gave an account of the changes in the spinning fields of this spider as development proceeds.

Larinioides patagiatus (Clerck) Figs. 402–408; Map 47

Araneus ocellatus Clerck, 1758:36, fig. 9 (pl. 1). Araneus patagiatus Clerck, 1758:38, fig. 10 (pl. 1); Locket and Millidge 1953:136, figs. 89c, 90b. Aranea dumetorum Fourcroy, 1785:534. Epeira ithaca McCook, 1894:152, fig. 3 (pl. 4). Epeira dumetorum: Kaston 1948:255, figs. 788 (pl. 37), 804 (pl. 38), 813 (pl. 39). Nuctenea patagiata: Levi 1974b:309, figs. 77–84, 100–102, 107, 112, 113, 120–123, 127.

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Figs. 402–408. Larinioides patagiatus. 402, female, dorsal view; 403, abdomen of female, dorsal view; 404, 405, epigynum: 404, ventral view; 405, posterior view; 406, spermathecae; 407, 408, palpus of male: 407, ventral view; 408, mesal view. e, embolus; ls, lateral sclerite; ma, median apophysis; term, terminal apophysis.

Larinioides patagiatus: Roberts 1985:212, fig. 95c; Marusik 1989:43; Heimer and Nentwig 1991:86, fig. 194. Male. Total length 6.39 ± 0.63 mm; carapace 3.20 ± 0.39 mm long, 2.67 ± 0.28 mm wide (10 specimens measured). Carapace yellowish to orange, sometimes paler at margins, with thin covering of recumbent white setae. Legs yellowish or pale orange, with tips and sometimes middle areas of segments dark; tibia II with several short stout macrosetae on prolateral surface. Abdomen with gray or reddish dorsal pattern. Palpus with short bifid median apophysis; median apophysis with its parts approximately equal in length (Fig. 407); embolus fin-

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Map 47. Collection localities of Larinioides patagiatus.

gerlike, without basal fold; terminal apophysis blunt at tip, narrowed near middle (Fig. 408). Female. Total length 8.63 ± 0.95 mm; carapace 3.85 ± 0.44 mm long, 3.25 ± 0.43 mm wide (10 specimens measured). Coloration as in male (Figs. 402, 403). Epigynum with tonguelike scape (Fig. 404); lateral sclerites broad, meeting at midline, with grooves and ridges (Fig. 405); spermathecae peanut-shaped (Fig. 406). Range. Alaska to Newfoundland, south to California and southern Texas; Europe, Asia. Comments. Specimens of L. patagiatus are distinguished from those of other species of Larinioides by the short, equal-sized parts of the median apophysis, by the tongue-like scape, and by the grooves and ridges on the lateral sclerites of the epigynum. Biology. Individuals of L. patagiatus are often found in the same situations as those of L. cornutus, but may be more common on buildings or bridges, particularly those closely surrounded by coniferous trees. Tyshchenko et al. (1985) 188

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reported on geographic variation in the web in northeast Asia. Kaston (1948) notes that, in New England, the web usually has 20–24 radii. The spider may or may not build a retreat; in the former case, a signal thread may be spun, and in the latter case the spider spends the day on a thread near the web and becomes active at night. Wiehle (1931) found mature males from spring to autumn in Germany, but autumn populations appeared to consist mainly of juveniles.

Larinioides sclopetarius (Clerck) Bridge Orbweaver Figs. 409–416; Map 48

Araneus sericatus Clerck, 1758:40, fig. 1 (pl. 2). Araneus sclopetarius Clerck, 1758:43, fig. 3 (pl. 2). Aranea undata Olivier, 1789:206; Wiehle 1931:90, figs. 130–133. Aranea ovigera Panzer, 1804:244, fig. 3 (pl. 174). Epeira undata: Kaston 1948:256, figs. 789 (pl. 37), 805 (pl. 38), 814, 815 (pl. 39), 2044, 2045 (pl. 123), 2046 (pl. 124). Nuctenea sclopetaria: Levi 1974b:310, figs. 85–88, 103, 104, 108, 114, 115, 124, 125, 128.

Map 48. Collection localities of Larinioides sclopetarius.

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Figs. 409–416. Larinioides sclopetarius. 409, female, dorsal view; 410, abdomen of female, dorsal view; 411, abdomen of female, ventral view; 412, 413, epigynum: 412, ventral view; 413, posterior view; 414, spermathecae; 415, 416, palpus of male: 415, ventral view; 416, mesal view. e, embolus; ls, lateral sclerite; ma, median apophysis; term, terminal apophysis.

Larinioides sclopetarius: Roberts 1985:212, fig. 95b; Ware and Opell 1989:150, fig. 2A; Heimer and Nentwig 1991:86, fig. 195. Male. Total length 8.17 ± 0.93 mm; carapace 4.13 ± 0.47 mm long, 3.47 ± 0.29 mm wide (10 specimens measured). Carapace grayish. Legs grayish; tibia II 190

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not swollen, lacking cluster of stout macrosetae. Abdomen with gray to nearly black dorsal pattern; pattern often interrupted near middle of dorsum; venter with conspicuous comma-shaped white markings. Palpus with large bifid median apophysis, the parts being unequal in size (Fig. 415); embolus fingerlike, without basal fold; terminal apophysis with thick blunt point, narrowed only at tip (Figs. 415, 416). Female. Total length 10.43 ± 1.18 mm; carapace 4.40 ± 0.42 mm long, 3.83 ± 0.49 mm wide (10 specimens measured). Coloration as in male (Figs. 409–411). Epigynum with slender fingerlike scape; scape nearly as long as epigynal plate (Fig. 412); lateral sclerites slender, smooth, not quite meeting at midline (Fig. 413); spermathecae rather large, round, with smaller secondary body posteriorly (Fig. 414). Range. British Columbia to Newfoundland, south to Utah, Oklahoma, and North Carolina; Europe, Asia. Levi (1974b) regards this spider as probably introduced, based on its close association with buildings and on the similarity of the range to that of Araneus diadematus. Comments. Specimens of L. sclopetarius are distinguished from those of other species of Larinioides by the lack of stout macrosetae on tibia II of males, by the apically narrowed terminal apophysis, by the long scape, and by the slender, almost-meeting lateral sclerites in the epigynum. Biology. The web, which may reach up to 70 cm in diameter, is built on buildings and bridges, often above or near water. In dense populations, the webs may overlap. According to Kaston (1948), a retreat is not usually built, the spider instead resting at the end of one of the radii or on a foundation line. Barrows (1915) performed simple experiments with individuals by the use of tuning forks. Adults may occur in all months, and the eggs are laid from June through August. Adult spiders are active mainly at night, but young ones may remain in their webs during the day as well (Wiehle 1931). Wiehle (1931) reviewed mating.

Genus Araniella Chamberlin & Ivie Members of the genus Araniella are small colorful orb weavers of trees, shrubs, or tall grass. The abdomen has 3 or more pairs of small black spots posterolaterally. The web is often built across the depression formed by a single leaf on a deciduous tree or shrub, and may be horizontal. The spider is diurnal, remaining at the hub of its web throughout the day. No retreat is made. Description. Total length 4.0–8.0 mm. Carapace yellow to brown, glabrous, rather wide and high at anterior end (Figs. 417, 418). Eyes small; posterior row of eyes straight or somewhat recurved. Legs yellow to brown, sometimes with distal segments darker toward tips; males with hook on coxa I and with groove on femur II, and with conspicuous erect macrosetae on all segments (Fig. 418). 191

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Abdomen broadly elliptical or ovoid (Figs. 417, 418), yellow, white, or greenish, with 3 (rarely 4) pairs of small circular black spots posterolaterally. Palpus of male with 2 or 3 patellar macrosetae; tegulum large, forming much of prolateral and ventral surfaces of genital bulb; median apophysis long, slender, often hooklike (Figs. 422, 423, 424); embolus long, slender, tapered to fine tip; conductor broad, often with 1 or more points (Figs. 423, 424); terminal apophysis long, broad, arched over distal end of bulb, overlying conductor and embolus (Figs. 422, 423, 424); paracymbium lobelike. Epigynum with short broad scape (Figs. 419, 425); scape appearing distinctly wrinkled, often broadly attached at base; spermathecae in two parts, a large, round or ovoid ventral part and a smaller darker dumbbell-shaped dorsal part (Figs. 421, 426, 427). Comments. Specimens of Araniella are distinguished from those of other araneid genera by the presence of 3 (rarely 2) dorsal macrosetae on the male palpal patella, by the slender hooklike median apophysis, and by the presence of a smaller darker second part in the spermathecae. The paired black spots at the posterolateral margins of the abdomen, though found in specimens throughout the genus, also occur in specimens of some species of Araneus, and are therefore not diagnostic. The genus Araniella comprises nine species, two of which are holarctic, and the others palaearctic (Levi 1974b, Blanke 1982). Both of the holarctic species are represented in Canada.

Key to species of Araniella l.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2(1).

Median apophysis of palpus abruptly curved (mesal view, Fig. 423); conductor not enfolding tips of embolus and terminal apophysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . displicata (Hentz) (p. 193)

2'.

Median apophysis of palpus smoothly curved (Fig. 424); conductor enfolding tips of embolus and terminal apophysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . proxima (Kulcz½ski) (p. 196)

3(1').

Scape of epigynum nearly as wide as epigynal plate (Fig. 419) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . displicata (Hentz) (p. 193)

3'.

Scape of epigynum distinctly narrower than epigynal plate (Fig. 425) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . proxima (Kulcz½ski) (p. 196)

Clé des espèces d’Araniella l.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

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2(1).

Courbure de l’apophyse médiane formant presque un angle (fig. 423), apex de l’apophyse terminale et de l’embolus libres des replis du conducteur . . . . . . . . . . . . . . . displicata (Hentz) (p. 193)

2'.

Courbure de l’apophyse médiane régulière (fig. 424); apex de l’apophyse terminale et de l’embolus reposant dans un replis du conducteur . . . . . . . . . . . . . . . . . . . . . . proxima (Kulczy½ski) (p. 196)

3(1').

Largeur du scape de l’épigyne similaire à la plaque de l’épigyne (fig. 419) . . . . . . . . . . . . . . . . . . . . . . . displicata (Hentz) (p. 193)

3'.

Largeur du scape de l’épigyne beaucoup plus étroite que l’épigyne. (fig. 425) . . . . . . . . . . . . . . . . . . . . . proxima (Kulczy½ski) (p. 196)

Araniella displicata (Hentz) Sixspotted Orbweaver Figs. 417–423; Map 49

Epeira displicata Hentz, 1847:476, fig. 17 (pl. 31); Emerton 1885:313, figs. 4 (pl. 34), 20 (pl. 36); Kaston 1948:258:, fig. 806 (pl. 38). Epeira decipiens Fitch, 1856:219. Epeira sexpunctata Keyserling, 1885:530, fig. 28 (pl. 13). Epeira alba Keyserling, 1885:530, fig. 20 (pl. 13). Araneus croaticus Kulczy½ski, 1905:233, figs. 22, 30 (pl. 7). Aranea displicata: Wiehle 1931:109, figs. 167–170. Araniella displicata: Chamberlin and Ivie 1942:76; Levi 1974b:294, plate 1, figs. 1–21; Blanke 1982:288, figs. 1, 2, 18, 21; Roberts 1985:212, 216, fig. 97e; Buckle and Roney 1995:978, figs. 4–6. Araniella displicata octopunctata Chamberlin and Ivie, 1942:76. Araneus displicatus: Locket and Millidge 1953:149, figs. 96b, 97c, 99c, 100c-e. Male. Total length 4.12 ± 0.18 mm; carapace 2.02 ± 0.10 mm long, 1.79 ± 0.10 mm wide (10 specimens measured). Carapace yellowish to brown, narrowed anteriorly to less than half greatest width. Legs yellowish; femur and tibia I with several long erect macrosetae, without curvature or swellings, sometimes with dark rings or with darkened segment tips (Fig. 418). Abdomen ovoid, off-white or yellowish, sometimes greenish or red, with 3 (rarely 4) pairs of small round black spots at posterolateral margins (Fig. 418). Palpus with 2 or 3 dorsal patellar macrosetae; median apophysis long, slender, abruptly hooked (mesal view, Fig. 422); embolus slender, straight or somewhat curved (depending on angle of viewing); conductor broad, with blunt, sometimes minutely toothed process covering base of median apophysis (Fig. 422); terminal apophysis slender, lying parallel to embolus (Figs. 422, 423). 193

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Figs. 417–423. Araniella displicata. 417, female, dorsal view; 418, male, dorsal view; 419, 420, epigynum; 419, ventral view; 420, posterior view; 421, spermathecae; 422, 423, palpus of male, mesal views. e, embolus; ma, median apophysis; teg, tegulum; term, terminal apophysis.

194

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Map 49. Collection localities of Araniella displicata.

Female. Total length 5.65 ± 0.69 mm; carapace 2.12 ± 0.18 mm long, 1.82 ± 0.10 mm wide (10 specimens measured). Carapace yellowish to brown, rather broad and high anteriorly (Fig. 417). Legs as in male, but with shorter macrosetae (Fig. 417). Abdomen broadly elliptical, colored as in male (Fig. 417). Epigynum with short broad scape (Fig. 419); scape nearly as wide as epigynal plate, traversed by many fine ridges and grooves, broad at base, spoon-shaped at tip, with several long pale setae; posterior plate broad to rather narrow, wider anteriorly (Fig. 420); spermathecae with large ovoid part, and small dumbbellshaped part (Fig. 421). Range. Alaska to Newfoundland, south to California, Arizona, and North Carolina; Europe, Asia. Comments. Specimens of A. displicata are distinguished from those of other species of Araniella by the abruptly hooked median apophysis, by the broad conductor process covering the base of the median apophysis, and by the broad epigynal scape. The possession of three (or four) pairs of small black spots on the abdominal dorsum is of some diagnostic value (Sacher 1990).

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Biology. Individuals of A. displicata are found in low shrubs and deciduous trees such as birch, maple, alder, hawthorn, and apple, more rarely in conifers. The web is often made across the concavity of a single deciduous leaf, where the spider sits during daylight. This exposure, coupled with the spiders’ small size, may contribute to the commonness of parasitized individuals in field populations (Blanke 1982). Juvenile individuals overwinter, and mature in May; there is one generation each year in northeastern U.S.A. and eastern Canada (Kaston 1948, Dondale 1961).

Araniella proxima (Kulczy½ski) Figs. 424–427; Map 50

Epeira proxima Kulczy½ski, 1885:19. Araniella cucurbitina: Levi 1974b:298 (part). Araniella proxima: Blanke 1982:289, figs. 10, 11, 18; Buckle and Roney 1995:978, figs. 1–3. Male. Total length 4.38 ± 0.18 mm; carapace 2.37 ± 0.10 mm long, 2.09 ± 0.14 mm wide (9 specimens measured). Carapace yellowish brown. Legs yellowish to orange; tibia I and II not curved or swollen, but with several stout erect macrosetae. Abdomen off-white or yellowish, ovoid, with 1–3 pairs of small circular black spots posterolaterally. Palpus with 2 or 3 patellar macrosetae; median apophysis long, slender, tapered toward tip, gently curved (Fig. 424); embolus long, slender; conductor with pointed spur at tip, with lobe enfolding tips of

Map 50. Collection localities of Araniella proxima.

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Figs. 424–427. Araniella proxima. 424, palpus of male, mesal view; 425, epigynum; 426, 427, spermathecae: 426, posterior view; 427, ventral view. con, conductor; e, embolus; ma, median apophysis; term, terminal apophysis.

embolus and terminal apophysis (Fig. 424); terminal apophysis long, slender, similar in width and length to embolus. Female. Total length 5.68 ± 0.48 mm; carapace 2.12 ± 0.27 mm long, 1.93 ± 0.15 mm wide (8 specimens measured). Carapace yellowish. Legs yellowish. Abdomen elliptical, colored as in male. Epigynum with scape; scape wrinkled, rather narrow, straight or somewhat curved, with several long pale setae (Fig. 425); posterior plate broad, abruptly narrowed posteriorly. Spermathecae in two parts, one rounded and the other elongated (Figs. 426, 427). Range. Alaska to Newfoundland; Europe, Asia. Comments. Specimens of A. proxima are distinguished from those of other species in the genus by the enfolding of the tips of the embolus and terminal apophysis by a lobe of the conductor, by the small spur on the conductor, by the narrow scape, and by the abruptly narrowed posterior sclerite of the epigynum. 197

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Sacher (1990) reported on the variation in number of small black spots on the abdominal dorsum. Blanke’s (1982) attempts to cross females of A. proxima with males of two European species were unsuccessful, though the males courted and attempted to copulate. Blanke regards individuals of A. proxima as most similar to those of A. opisthographa (Kulczy½ski), a species not known to be represented in North America. Biology. Specimens of A. proxima have been taken by sweep nets on birch, poplar, and coniferous foliage in boreal forest. Blanke (1982) described sexual behavior.

Genus Araneus Clerck Representatives of the genus Araneus are a diverse assemblage of orb weavers, some being more than 25 mm in body length and constructing webs with a catching area of 60 cm or more in diameter, and others less than 3 mm in length and building inconspicuous orbs as small as 7 cm in diameter. Individuals of some species are forest dwellers [A. nordmanni (Thorell), A. saevus (L. Koch), A. bicentenarius (McCook), A. juniperi (Emerton)], whereas others are clearly meadow or bog inhabitants [A. trifolium (Hentz), A. corticarius (Emerton), A. iviei (Archer), A. groenlandicola (Strand), A. pratensis (Emerton), A. guttulatus (Walckenaer)]. Some are most abundant around buildings [(A. diadematus Clerck, A. cavaticus (Keyserling), A. gemmoides Chamberlin & Ivie)]. The webs are usually vertical or nearly so, with 18–30 radii and with a nearby silk-lined retreat. The spider hunts from the hub from early evening to dawn, then retires to the retreat during daylight hours. The overwintering stage, with some exceptions, appears to be the egg, and the spiders mature and reproduce in late summer and early autumn. Description. Total length of males 2.7–19.0 mm, of females 2.5–25.0 mm. Carapace rather low, narrowed toward front, usually covered with shiny setae. Median eyes usually larger than lateral eyes; anterior median eyes often protruding anteriorly (Figs. 436, 517). Leg I longer than leg IV; coxa I of males usually with distal hook; coxa II sometimes with ventral spur (Fig. 4); tibia II often curved and armed with cluster of stout macrosetae. Abdomen spherical, triangular, or somewhat elongate, often with paired humps anterolaterally, hairy in individuals of large species. Palpus of male with 2 patellar macrosetae; tibia conical, thickened laterally; paracymbium small, basal; median apophysis with one or more pointed hooklike spurs at one or both ends (Figs. 433, 455, 472); conductor situated at edge of tegulum, often pale and flexible, sometimes with small tooth on base; embolus usually hidden in unexpanded bulb by conductor, often with lamella, with sclerotized “cap” in unmated males of some species (note that it may be necessary to pry aside some of the sclerites of the bulb in order to expose the embolus, where the latter is hidden in the unexpanded bulb); terminal apoph-

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ysis often prominent, pronglike (Fig. 464), sometimes with small hooks or spines; subterminal apophysis usually platelike, often rugose. Epigynum (Figs. 430, 431, 460, 461) with scape; scape usually with transverse ridges and grooves, short to long, attached to base formed of lateral sclerites but sometimes lost in mated females, with posterior plate (Figs. 432, 462), often with paired basal lamellae (Fig. 432); spermathecae (Figs. 441, 448, 521) round, elliptical or kidney-shaped. Comments. Restriction of the genus Araneus by the exclusion of formerly included groups such as Araniella, Larinioides, and Aculepeira has helped much to produce homogeneity in all of these genera. Even so, the characters usually given to diagnose Araneus (see Levi 1991) are either not expressed in some members of the genus or appear as well in individuals of other genera, or both. For example, a hairy, subspherical to triangular abdomen so common among adults of the large species of Araneus is replaced by the smooth abdomens and other shapes in adults of the smaller species. Abdominal humps are also common among but not exclusive to females of Araneus, and are also found in representatives of other araneid genera. The same applies to the long “wrinkled” (i.e., ridged and grooved) epigynal scape, the basal attachment of the scape, the spurs found on the median apophysis, the situation of the conductor at the rim of the tegulum, and the presence of an embolus cap in unmated males. Hence we find no single character that is truly diagnostic for the members of the genus Araneus, and further research appears to be needed. The genus Araneus includes more than 600 world species. Levi (1971, 1973) treated 49 species in America north of Mexico; of these, 22 are represented in Canada.

Key to species of Araneus 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2(1).

Coxa I with distal hook (Fig. 4) . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2'.

Coxa I without hook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3(2).

Median apophysis with 1 or 2 main spurs (Figs. 449, 455, 472) . . 5

3'.

Median apophysis with 3 main spurs (Figs. 433, 442) . . . . . . . . . 4

4(3').

Median apophysis with 1 spur at base, 2 at free (distal) end (Fig. 433) . . . . . . . . . . . . . . . . . . . . . . . . . . bicentenarius (McCook) (p. 209)

4'.

Median apophysis with 3 main spurs at distal end (Fig. 442) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . thaddeus (Hentz) (p. 211)

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5(3).

Median apophysis with 2 main spurs at distal end, none at base (Fig. 449) . . . . . . . . . . . . . . . . . . . . . pegnia (Walckenaer) (p. 213)

5'.

Median apophysis with 1 main spur at each end (distal spur may be broad and somewhat flattened) (Figs. 456, 472, 487) . . . . . . . . . . 6

6(5').

Coxa II with spur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

6'.

Coxa II without spur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

7(6).

Terminal apophysis short, little curved. Abdomen with cross-shaped pattern of white spots (Fig. 455, 456). . . diadematus Clerck (p. 216)

7'.

Terminal apophysis longer, distinctly curved. Abdomen without cross-shaped pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

8(7').

Embolus with slender blunt tip and angular distal piece (Figs. 463, 465) . . . . . . . . . . . . . . . . . . . . . . . . . nordmanni (Thorell) (p. 219)

8'.

Embolus with thicker tip, without angular distal piece (Figs. 472, 474, 479, 481) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

9(8').

Embolus with single short process on circular base (Fig. 474) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . marmoreus Clerck (p. 221)

9'.

Embolus with 2 or more processes on base (Fig. 481) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . saevus (L. Koch) (p. 224)

10(6').

Median apophysis more than twice as long as wide (Fig. 486) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . corticarius (Emerton) (p. 226)

10'.

Median apophysis little longer than wide (Fig. 493) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . washingtoni Levi (p. 228)

11(2').

Median apophysis with 3 main spurs (Figs. 500, 501, 507, 514, 515) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

11'.

Median apophysis with 1 or 2 main spurs, or none (Figs. 522, 528, 536, 543, 550) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

12(11).

Embolus distinctly longer than embolar lamella (Fig. 502). Distal spurs on median apophysis long, curved (Figs. 500, 501) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . groenlandicola (Strand) (p. 230)

12'.

Embolus approximately equal in length to its embolar lamella. Distal spurs on median apophysis otherwise . . . . . . . . . . . . . . . . . . . . 13

13(12').

Embolus and its embolar lamella stout (Fig. 509) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . trifolium (Hentz) (p. 233)

13'.

Embolus and its embolar lamella slender, conical (Fig. 516) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . yukon Levi (p. 235)

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14(11').

Median apophysis nearly as long as genital bulb, oriented longitudinally (Figs. 522, 523). Abdomen elliptical in outline, smooth, with paired dark longitudinal bands (Fig. 517) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pratensis (Emerton) (p. 237)

14'.

Median apophysis much shorter than genital bulb, oriented transversely or nearly so. Abdomen angular, with setae, without paired dark longitudinal bands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

15(14').

Tip of embolus broad, blunt (Fig. 530) . . . . iviei (Archer) (p. 240)

15'.

Tip of embolus pointed (Figs. 538, 545, 552, 559, 574, 582, 591) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

16(15').

Embolus straight or smoothly curved (Figs. 545, 552) . . . . . . . . 17

16'.

Embolus in tight curl (Fig. 538) . . . alboventris (Emerton) (p. 242)

17(16).

Carapace width greater than 4.0 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cavaticus (Keyserling) (p. 244)

17'.

Carapace width less than 4.0 mm . . . . . . . . . . . . . . . . . . . . . . . . 18

18(17').

Embolus strongly curved, with tip directed toward base of genital bulb (Figs. 574, 582, 591) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

18'.

Embolus less curved, with tip directed toward tip of genital bulb (Figs. 550, 557, 567) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

19(18').

Tip of embolus making acute angle with base (Fig. 552) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gemmoides Chamberlin & Ivie (p. 246)

19'.

Tip of embolus not making angle with base (Figs. 559, 567) . . . 20

20(19')

Embolus short, readily seen in mesal view (Fig. 557) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gemma McCook (p. 249)

20'.

Embolus much longer, largely concealed in mesal view by conductor (Fig. 565) . . . . . . . . . . . . . . . . . . montereyensis (Archer) (p. 251)

21(18).

Embolus slender (Figs. 572–574) . . . . juniperi (Emerton) (p. 254)

21'.

Embolus stouter (Figs. 580–582) . . . . . . . . . . . . . . . . . . . . . . . . 22

22(21').

Terminal apophysis stout (Fig. 581) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cingulatus (Walckenaer) (p. 256)

22'.

Terminal apophysis slender (Fig. 592) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . guttulatus (Walckenaer) (p. 259)

23(1').

Epigynum with paired basal lamellae (Figs. 432, 462, 471, 478, 542) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

23'.

Epigynum without basal lamellae (Figs. 438, 454, 518) . . . . . . . 36

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24(23).

Abdomen with paired anterolateral humps (Figs. 428, 458, 459, 475, 482, 489, 539, 546, 553) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

24'.

Abdomen without humps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

25(24).

Abdominal humps extending laterally beyond margins of abdomen (Fig. 482) . . . . . . . . . . . . . . . . . . . . corticarius (Emerton) (p. 226)

25'.

Abdominal humps not extending laterally . . . . . . . . . . . . . . . . . 26

26(25').

Scape long, its length twice or more width of epigynum (Figs. 430, 431, 476, 477) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

26'.

Scape shorter, its length less than twice width of epigynum (Figs. 460, 461, 490, 491, 540, 541, 547, 548, 554, 555) . . . . . . 28

27(26).

Posterior plate of epigynum broad, pale (Fig. 432) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . bicentenarius (McCook) (p. 209)

27'.

Posterior plate broad ventrally, narrowed dorsally, darker (Fig. 478) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . saevus (L. Koch) (p. 224)

28(26').

Scape with conspicuous transverse ridges and grooves (Figs. 460, 490, 540) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

28'.

Scape almost devoid of transverse ridges and grooves (Figs. 547, 554) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

29(28).

Scape with conspicuous kink near middle (Figs. 490, 491) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . washingtoni Levi (p. 228)

29'.

Scape without kink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

30(29').

Posterior plate of epigynum heart-shaped (Fig. 462) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . nordmanni Thorell (p. 219)

30'.

Posterior plate of epigynum V-shaped (Fig. 542) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cavaticus (Keyserling) (p. 244)

31(28').

Scape small, triangular (Fig. 547) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gemmoides Chamberlin & Ivie (p. 246)

31'.

Scape larger, more elongate (Figs. 554, 555) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gemma McCook (p. 249)

32(24').

Basal lamellae of epigynum large, triangular, nearly as long as lateral sclerites (Fig. 471) . . . . . . . . . . . . . marmoreus Clerck (p. 221)

32'.

Basal lamellae smaller, usually slender, much shorter than lateral sclerites (Figs. 499, 506, 513, 527) . . . . . . . . . . . . . . . . . . . . . . . 33

33(32').

Basal lamellae comma-shaped (Fig. 527) . . . iviei (Archer) (p. 240)

33'.

Basal lamellae shaped otherwise (Figs. 499, 506, 513) . . . . . . . . 34

34(33').

Scape broad at base, tapered toward tip (Figs. 497, 511) . . . . . . 35

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34'.

Scape parallel at sides (Fig. 504) . . . . . . trifolium (Hentz) (p. 233)

35(34).

Epigynum with broad depression on each side of scape (Fig. 511) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . yukon Levi (p. 235)

35'.

Epigynum lacking depression on each side of scape (Fig. 497) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . groenlandicola (Strand) (p. 230)

36(23').

Scape greatly elongated, with distinct transverse grooves and ridges (Figs. 452, 453). Abdomen with white spots forming cross-shaped pattern (Fig. 451) . . . . . . . . . . . . . . . . . diadematus Clerck (p. 216)

36'.

Scape much shorter, with few transverse grooves and ridges (Figs. 439, 446, 519, 533, 562, 569, 577, 587). Abdomen with pattern otherwise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

37(36').

Abdomen elliptical in outline, with paired longitudinal dark bands (Fig. 517) . . . . . . . . . . . . . . . . . . . . . pratensis (Emerton) (p. 237)

37'.

Abdomen rounded or triangular in outline, lacking paired longitudinal dark bands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

38(37').

Posterior plate of epigynum as wide as entire epigynum, clearly rectangular in outline (Fig. 438) . . . . . . . . . thaddeus (Hentz) (p. 211)

38'.

Posterior plate narrower than epigynum, and outline of the plate of a different shape (Figs. 447, 534, 563, 570, 578, 589) . . . . . . . . . . 39

39(38').

Posterior plate rounded in outline (Fig. 447) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pegnia (Walckenaer) (p. 213)

39'.

Posterior plate otherwise (Figs. 534, 563, 570, 578, 589) . . . . . . 40

40(39').

Scape approximately straight (Figs. 533, 562) . . . . . . . . . . . . . . 41

40'.

Scape usually angular or tortuous (Figs. 577, 587, 588) . . . . . . . 42

41(40).

Abdomen with large dark median mark (Figs. 531, 532) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . alboventris (Emerton) (p. 242)

41'.

Abdomen dark anterolaterally, with paired dark oblique marks posteriorly (Figs. 560, 561) . . . . . . . . . . montereyensis Archer (p. 251)

42(40').

Lateral sclerites of epigynum hornlike (posterior view, Fig. 589) . . . . . . . . . . . . . . . . . . . . . . . . . . . . guttulatus (Walckenaer) (p. 259)

42'.

Lateral sclerites not hornlike . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

43(42').

Copulatory openings slitlike (Figs. 569–571). Posterior plate with anterior margin straight (Fig. 570) . . . . juniperi (Emerton) (p. 254)

43'.

Copulatory openings wider (Figs. 577–579). Posterior plate with anterior margin concave (Fig. 578) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cingulatus (Walckenaer) (p. 256) 203

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Clé des espèces d’Araneus 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2(1).

Coxa I munie d’un crochet terminal (fig. 4) . . . . . . . . . . . . . . . . . 3

2'.

Coxa I sans crochet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

3(2).

Apophyse médiane munie de 1 ou 2 éperons principaux (figs. 449, 455, 472) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3'.

Apophyse médiane munie de 3 éperons principaux (figs. 433, 442) . ...................................................4

4(3').

Apophyse médiane munie d’un éperon en position basale et de 2 en position terminale (fig. 433) . . . . bicentenarius (McCook) (p. 209)

4'.

Apophyse médiane munie de 3 éperons principaux en position terminale (fig. 442) . . . . . . . . . . . . . . . . . . . . thaddeus (Hentz) (p. 211)

5(3).

Apophyse médiane munie de 2 éperons principaux en position terminale, aucun éperon en position basale (fig. 449) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pegnia (Walckenaer) (p. 213)

5'.

Apophyse médiane munie d’un éperon principal à chaque extrémité (l’éperon en position terminale quelquefois large et aplati) (figs. 456, 472, 487) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

6(5').

Coxa II munie d’un éperon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

6'.

Coxa II sans éperon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

7(6).

Apophyse terminale courte, quelque peu recourbée. Abdomen orné de taches blanches formant un motif évoquant une croix (figs. 455, 456) . . . . . . . . . . . . . . . . . . . . . . . . . . diadematus Clerck (p. 216)

7'.

Apophyse terminale allongée, nettement recourbée. Abdomen sans motif en forme de croix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

8(7').

Apex de l’embolus étroit et arrondi, partie terminale formant un angle (figs. 463, 465) . . . . . . . . . . . . . . . . nordmanni (Thorell) (p. 219)

8'.

Apex de l’embolus plus large, partie terminale ne formant pas d’angle (figs. 472, 474, 479, 481) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

9(8').

Embolus arborant une seule projection reposant sur une base arrondie (fig. 474) . . . . . . . . . . . . . . . . . . . . . . . marmoreus Clerck (p. 221)

9'.

Embolus arborant deux projections (ou plus) reposant sur une base nettement moins arrondie (fig. 481) . . . . saevus (L. Koch) (p. 224)

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10(6').

Apophyse médiane plus de 2 fois plus longue que large (fig. 486) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . corticarius (Emerton) (p. 226)

10'.

Apophyse médiane à peine plus longue que large (fig. 493) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . washingtoni Levi (p. 228)

11(2').

Apophyse médiane munie de 3 éperons (figs. 500, 501, 507, 514, 515) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

11'.

Apophyse médiane munie de 2, 1 ou aucune éperon (figs. 522, 528, 536, 543, 550) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

12(11).

Embolus nettement plus long que la lame de l’embolus (fig. 502). Éperons de la partie terminale de l’apophyse médiane longs et courbés (figs. 500, 501) . . . . . . . . . . . groenlandicola (Strand) (p. 230)

12'.

Embolus de longueur similaire à la lame de l’embolus. Éperons de la partie terminale de l’apophyse médiane différents . . . . . . . . . . . 13

13(12').

Embolus et lame de l’embolus robustes (fig. 509) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . trifolium (Hentz) (p. 233)

13'.

Embolus et lame de l’embolus étroits et minces, de forme conique (fig. 516) . . . . . . . . . . . . . . . . . . . . . . . . . . . . yukon Levi (p. 235)

14(11').

Apophyse médiane presque aussi longue que le bulbe génital, et apophyse orientée longitudinalement (figs. 522, 523). Contour de l’abdomen en forme d’ellipse, abdomen lisse et orné d’une paire de bandes longitudinales sombres (fig. 517) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pratensis (Emerton) (p. 237)

14'.

Apophyse médiane beaucoup plus courte que le bulbe génital, et apophyse orientée transversalement, ou presque. Abdomen pourvu de soies, formant des angles et sans bande longitudinale sombre . . 15

15(14').

Apex de l’embolus large et arrondi (fig. 530) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iviei (Archer) (p. 240)

15'.

Apex de l’embolus se terminant en pointe (figs. 538, 545, 552, 559, 574, 582, 591) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

16(15').

Embolus droit ou à peine recourbé (figs. 545, 552) . . . . . . . . . . 17

16'.

Embolus formant une courbe très serrée (fig. 538) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . alboventris (Emerton) (p. 242)

17(16).

Largeur du céphalothorax plus de 4.0 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cavaticus (Keyserling) (p. 244)

17'.

Largeur du céphalothorax moins de 4.0 mm . . . . . . . . . . . . . . . 18

18(17').

Courbure de l’embolus très prononcée, orientée vers la base du bulbe génital (figs. 574, 582, 591) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 205

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18'.

Courbure de l’embolus moins prononcée, qui pointe en direction de l’apex du bulbe génital (figs. 550, 557, 567) . . . . . . . . . . . . . . . 19

19(18').

Apex de l’embolus formant un angle aigu avec la partie basale (fig. 552) . . . . . . . . . . . . . gemmoides Chamberlin & Ivie (p. 246)

19'.

Apex de l’embolus ne formant pas d’angle avec la partie basale (figs. 559, 567) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

20(19')

Embolus court, facilement visible (fig. 557) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gemma (McCook) (p. 249)

20'.

Embolus beaucoup plus long, mais caché en grande partie par le conducteur (fig. 565) . . . . . . . . . . . . montereyensis (Archer) (p. 251)

21(18).

Embolus étroit (figs. 572–574) . . . . . . . juniperi (Emerton) (p. 254)

21'.

Embolus plus large (figs. 580–582) . . . . . . . . . . . . . . . . . . . . . . . 22

22(21').

Apophyse terminale robuste (fig. 581) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cingulatus (Walckenaer) (p. 256)

22'.

Apophyse terminale plus élancée (fig. 592) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . guttulatus (Walckenaer) (p. 259)

23(1').

Épigyne munie d’une paire de lames basales (figs. 432, 462, 471, 478, 542) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

23'.

Épigyne sans lame basale (figs. 438, 454, 518) . . . . . . . . . . . . . 36

24(23).

Abdomen muni d’une paire de bosses en position antéro-latérale (figs. 428, 458, 459, 475, 482, 489, 539, 546, 553) . . . . . . . . . 25

24'.

Abdomen sans bosse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

25(24).

Bosses abdominales qui se prolongent latéralement au-delà du contour de l’abdomen (fig. 482) . . . . . . corticarius (Emerton) (p. 226)

25'.

Bosses abdominales ne se prolongent pas latéralement . . . . . . . 26

26(25').

Scape 2 fois plus long que la largeur de l’épigyne (figs. 430, 431, 476, 477) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

26'.

Scape plus court, moins de 2 fois la largeur de l’épigyne (figs. 460, 461, 490, 491, 540, 541, 547, 548, 554, 555) . . . . . . . . . . . . . . . 28

27(26).

Plaque postérieure de l’épigyne de couleur pâle, en forme d’ellipse (fig. 432) . . . . . . . . . . . . . . . . . . . bicentenarius (McCook) (p. 209)

27'.

Plaque postérieure de l’épigyne de couleur sombre, large dans la partie antérieure et retrécissant vers l’arrière (fig. 478) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . saevus (L. Koch) (p. 224)

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28(26').

Scape garni de carènes et de sillons transverses marqués (figs. 460, 490, 540) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

28'.

Scape presque entièrement dépourvu de carènes et de sillons transverses (figs. 547, 554) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

29(28).

Scape tordu près de son centre (figs. 490, 491) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . washingtoni Levi (p. 228)

29'.

Scape sans torsion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

30(29').

Plaque postérieure de l’épigyne cordiforme (fig. 462) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . nordmanni Thorell (p. 219)

30'.

Plaque postérieure de l’épigyne en V (fig. 542) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cavaticus (Keyserling) (p. 244)

31(28').

Scape petit et triangulaire (fig. 547) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gemmoides Chamberlin & Ivie (p. 246)

31'.

Scape plus gros et allongé (figs. 554, 555) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . gemma McCook (p. 249)

32(24').

Lames basales de l’épigyne larges, triangulaires, presque aussi longues que les sclérites latéraux (fig. 471) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . marmoreus Clerck (p. 221)

32'.

Lames basales de l’épigyne plus petites, habituellement étroites, beaucoup plus courtes que les sclérites latéraux (figs. 499, 506, 513, 527) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

33(32').

Lames basales en forme de virgule (fig. 527) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iviei (Archer) (p. 240)

33'.

Lames basales de forme différentes (figs. 499, 506, 513) . . . . . . . 34

34(33').

Base du scape plutôt large qui va en rétrécissant vers l’apex (figs. 497, 511) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

34'.

Bordures du scape parallèles (fig. 504) . . trifolium (Hentz) (p. 233)

35(34).

Épigyne formé d’une dépression de chaque côté du scape (fig. 511) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . yukon Levi (p. 235)

35'.

Épigyne sans dépression latérale (fig. 497) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . groenlandicola (Strand) (p. 230)

36(23').

Scape très allongé, muni de carènes et de sillons transverses marquées (figs. 452, 453). Abdomen orné de taches blanches formant un motif évoquant une croix (fig. 451) . . . diadematus Clerck (p. 216)

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36'.

Scape beaucoup plus court, munis de peu de carènes et de sillons transverses (figs. 439, 446, 519, 533, 562, 569, 577, 587). Abdomen sans taches blanches évoquant une croix . . . . . . . . . . . . . . . . . . 37

37(36').

Contour de l’abdomen en forme d’ellipse, abdomen orné d’une paire de bandes longitudinales sombres (fig. 517) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pratensis (Emerton) (p. 237)

37'.

Contour de l’abdomen rond ou triangulaire, abdomen sans bandes longitudinales sombres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

38(37').

Plaque postérieure de l’épigyne aussi large que l’épigyne elle-même, de forme nettement rectangulaire (fig. 438) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . thaddeus (Hentz) (p. 211)

38'.

Plaque postérieure de l’épigyne plus étroite que l’épigyne et de forme différente (figs. 447, 534, 563, 570, 578, 589) . . . . . . . . . . . . . . 39

39(38').

Contour de la plaque postérieure de l’épigyne arrondi (fig. 447) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pegnia (Walckenaer) (p. 213)

39'.

Plaque postérieure de l’épigyne de forme différente (figs. 534, 563, 570, 578, 589) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

40(39').

Scape presque droit (figs. 533, 562) . . . . . . . . . . . . . . . . . . . . . . 41

40'.

Scape habituellement tordu ou formant un angle(figs. 577, 587, 588) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

41(40).

Centre de l’abdomen orné d’une grande tache sombre (figs. 531, 532) . . . . . . . . . . . . . . . . . . . . . . . . . . . . alboventris (Emerton) (p. 242)

41'.

Partie antéro-latérale de l’abdomen sombre, et surface postérieure de l’abdomen ornée d’une paire de traits obliques et sombres (figs. 560, 561) . . . . . . . . . . . . . . . . . . . . . . . . montereyensis Archer (p. 251)

42(40').

Sclérites latéraux de l’épigyne en forme de corne (vue postérieure, fig. 589) . . . . . . . . . . . . . . . . . . . guttulatus (Walckenaer) (p. 259)

42'.

Sclérites latéraux de l’épigyne de forme différente . . . . . . . . . . . 43

43(42').

Ouvertures copulatoires en forme de fissure (figs. 569–571). Marge antérieure de la plaque postérieure de l’épigyne droite (fig. 570) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . juniperi (Emerton) (p. 254)

43'.

Ouvertures copulatoires en forme de demi-lune et plus grandes (figs. 577–579). Marge antérieure de la plaque postérieure de l’épigyne concave (fig. 578) . . . . . . . . . cingulatus (Walckenaer) (p. 256)

208

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Araneus bicentenarius (McCook) Figs. 428–435; Map 51

Epeira bicentennaria McCook, 1888:195, figs. 3, 5. McCook’s original spelling gave this spelling (with two n’s), but later corrected this to one. The International Commission on Zoological Nomenclature (1999) treats the emended spelling as correct. Epeira angulata var. bicentenaria: McCook 1894:186, figs. 3–5 (pl. 10), 2–4 (pl. 11). Aranea bicentenaria: Archer 1951:31, figs. 68, 78. Aranea kisatchia Archer, 1951:27, fig. 69. Araneus bicentenarius: Levi 1971:143, figs. 15–26, plate 3; Kaston 1977:31, fig. 26. Male. Total length 7.00, 10.19, 11.52 mm; carapace 5.62, 5.68, 6.50 mm long, 4.60, 4.84, 5.01 mm wide (3 specimens measured). Carapace dark brown. Legs brown, with dark rings; coxa I with hook; coxa II with spur; tibia II stout, with strong macrosetae. Abdomen with paired humps anterolaterally, usually dark, with pattern of angular dark marks posteriorly (Figs. 428, 429); venter dark brown to black, sometimes with median pale area. Palpus with median apophysis, embolus, and conductor on mesal surface; median apophysis boat-shaped, with 1 basal spur and 2 distal spurs (Fig. 433); conductor large, flat, toothed at margin

Map 51. Collection localities of Araneus bicentenarius.

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Figs. 428–435. Araneus bicentenarius. 428, 429, abdomen of female, dorsal views; 430– 432, epigynum: 430, ventral view; 431, lateral view; 432, posterior view; 433–435, palpus of male: 433, mesal view; 434, ventral view; 435, embolus and terminal apophysis. bla, basal lamella; con, conductor; e, embolus; ma, median apophysis; pp, posterior plate; s, scape; teg, tegulum; term, terminal apophysis.

(Figs. 433, 434); embolus broad at base, abruptly tapered to slender point (Fig. 435); terminal apophysis large, curved, bulbous (Figs. 433, 434). Female. Total length 15.66 (13.19–17.70) mm; carapace 6.24 (5.01–7.01) mm long, 5.83 (5.60–6.03) mm wide (4 specimens measured). Coloration essentially as in male, but abdomen sometimes with contrasting color patterns (Fig. 429). Epigynum with long ridged scape (Figs. 430, 431); scape reflexed at

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base, flattened toward tip (Fig. 431); posterior plate broad, narrowed posteriorly to fine point (Fig. 432); basal lamellae small, elongate (Fig. 432). Range. Minnesota to Nova Scotia, south to Texas and northern Florida. Comments. Specimens of A. bicentenarius are distinguished from those of other species of Araneus by the bulbous curved terminal apophysis and by the long broad flat distal part of the scape. Only males of A. bicentenarius and those of the U.S. Pacific coastal species A. andrewsi (Archer) possess a fringe of small sharp teeth on the margin of the conductor (Figs. 433, 434). Biology. Individuals of A. bicentenarius attach their large orb webs to the trunks of forest trees (Levi 1971). When resting among lichens, the spider becomes almost perfectly camouflaged. Beckwitt and Arcidiacono (1994) determined the site of genes for silk proteins in this species.

Araneus thaddeus (Hentz) Lattice Orbweaver Figs. 436–443; Map 52

Epeira thaddeus Hentz, 1847:473, fig. 6 (pl. 31); Emerton 1909:200, fig. 2 (pl. 5); Kaston 1948:259, figs. 807–809 (pl. 38), 826, 827 (pl. 40).

Map 52. Collection localities of Araneus thaddeus.

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Figs. 436–443. Araneus thaddeus. 436, female, dorsal view; 437, abdomen of female, ventral view; 438–440, epigynum: 438, posterior view; 439, ventral view; 440, lateral view; 441, spermathecae; 442, 443, palpus of male: 442, mesal view; 443, ventral view. con, conductor; ma, median apophysis; spt, spermatheca; term, terminal apophysis.

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Epeira baltimorensis Keyserling, 1880:305, fig. 8 (pl. 4). Araneus thaddeus: Petrunkevitch 1911:319; Levi 1973:543, plate 10, figs. 4, 415–425; 1991:239, figs. 235–239. Neosconella thaddeus Archer, 1951:39, fig. 41. Male. Total length 4.70 mm; carapace 2.90 mm long, 2.20 mm wide (1 specimen measured). Carapace yellowish, somewhat darker mesally. Legs yellowish or orange, with darker rings; coxa I with hook; tibia II little thicker than tibia I, with few slender macrosetae. Abdomen off-white dorsally, usually with small paired oblique streaks on posterior half and paler areas anteriorly (Fig. 436); venter with distinct white spot bordered laterally and posteriorly with black (Fig. 437). Palpus with compact genital bulb; median apophysis small, with 3 distal teeth, no basal tooth (Figs. 442, 443); embolus broad at base, tapered to fine curved dark tip; conductor angular (Fig. 442); terminal apophysis with tip angular, dark (Figs. 442, 443). Female. Total length 6.20 mm; carapace 2.50 mm long, 2.20 mm wide (1 specimen measured). Coloration essentially as in male (Figs. 436, 437). Epigynum with short scape; scape rather narrow, with sides parallel (Figs. 439, 440); posterior plate large, pale, rectangular in outline (Fig. 438); spermathecae large, elliptical, touching (Fig. 441). Range. Utah and southern Manitoba to northern New York and Massachusetts, south to Arizona and central Mexico. Comments. Specimens of A. thaddeus are distinguished from those of other species in the genus by the presence of three distal spurs and no basal spur on the median apophysis, by the parallel sides of the scape, and by the large rectangular posterior plate of the epigynum. Biology. Individuals of A. thaddeus build small vertical webs of 15–20 cm diameter among the leaves of forest trees, hedges, and ivy-covered walls, and also on fences and bare walls. Kaston (1948) counted about 25 radii, with sometimes a vacant sector in the upper half. A retreat and signal thread are usually included with the web. Adults appear in the autumn.

Araneus pegnia (Walckenaer) Figs. 444–450; Map 53

Epeira pegnia Walckenaer, 1841:80; Kaston 1948:260, figs. 810 (pl.38), 828, 829 (pl. 40), 2050 (pl. 125). Epeira tytera Walckenaer, 1841:81. Epeira globosa Keyserling, 1865:820, figs. 19, 20 (pl. 18). Epeira triaranea McCook, 1876:200; Emerton 1885:315, figs. 9 (pl. 34), 6, 7 (pl. 36).

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Figs. 444–450. Araneus pegnia. 444, 445, abdomen of female: 444, dorsal view; 445, ventral view; 446, 447, epigynum: 446, ventral view; 447, posterior view; 448, spermathecae; 449, 450, palpus of male: 449, ventral view; 450, embolus. ls, lateral sclerite; ma, median apophysis; pp, posterior plate; spt, spermathecae; term, terminal apophysis.

Epeira solersioides O. Pickard-Cambridge, 1889:25, fig. 15 (pl. 7). Araneus pegnia: Petrunkevitch 1911:308; Levi 1973:546, plate 10, figs. 5, 426–438; 1991:236, figs. 228–234. Male. Total length 4.70 mm; carapace 2.90 mm long, 2.20 mm wide (1 specimen measured). Carapace yellowish brown. Legs yellowish brown, sometimes 214

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Map 53. Collection localities of Araneus pegnia.

with darker rings; coxa I with hook; tibia II thicker than other tibiae, with several long slender macrosetae. Abdomen with pale ovoid area, which is bordered with black anteriorly, and with 3 pairs of small black spots or oblique marks posteriorly (Fig. 444). Palpus with compact genital bulb; median apophysis small, with 2 spurs at distal end, none at base (Fig. 449); embolus stout, curved at tip (Figs. 449, 450); conductor angular; terminal apophysis curved, with angular pointed tip (Fig. 449). Female. Total length 6.10, 6.56, 7.06 mm; carapace 2.49, 2.57, 2.70 mm long, 1.99, 2.20, 2.30 mm wide (3 specimens measured). Coloration much as in male but abdominal pattern more distinct (Fig. 444); venter with off-white area and black area (Fig. 445). Epigynum with scape short, variable in outline (Fig. 446); lateral sclerites arched far laterally (Fig. 447); posterior plate approximately heart-shaped (Fig. 447); spermathecae large, kidney-shaped, not touching (Fig. 448). Range. Northern Indiana to northern New York and Massachusetts, south to California, Florida, Venezuela, coastal Ecuador, and the West Indies. Comments. Specimens of A. pegnia are distinguished from those of other species in the genus by the possession of two distal spurs and no basal spurs on the median apophysis, by the thick curved embolus, by the laterally arched lateral sclerites and heart-shaped posterior sclerite of the epigynum. 215

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Biology. Individuals of A. pegnia build orb webs in shrubs on bogs and similar habitats. The orb is approximately 10 cm in diameter, has about 30 radii, and there may be an open sector in the upper half. There is a retreat, which is connected to the hub by a signal thread, and also a large, loose irregular mass of threads “similar to that in the web of Metepeira labyrinthea” (Kaston 1948).

Araneus diadematus Clerck Cross Orbweaver Figs. 451–457; Map 54

Araneus diadematus Clerck, 1758:25, fig. 4 (pl. 1); Locket and Millidge 1953:127, figs. 84a, 85a, 86a, 87a; Levi 1971:147, figs. 34–41, 95, 184–186; Roberts 1985:208, fig. 93a. Aranea diadema: Wiehle 1931:70, figs. 103–108; Kaston 1948:249, figs. 779–782 (pl. 37). Male. Total length 8.28 ± 1.19 mm; carapace 4.51 ± 0.81 mm long, 3.54 ± 0.63 mm wide (10 specimens measured). Carapace yellowish brown, darker at lateral margins and at midline. Legs yellowish brown, with dark rings; coxa I with hook; tibia II stout, curved, and provided with two longitudinal rows of short stout macrosetae. Abdomen hairy, yellowish brown, with cross-shaped pattern of white spots anteriorly, and with oblique dark marks posteriorly (Fig 451). Palpus with large prominent median apophysis; median apophysis with sharp spur near base and with flattened spur at distal end (Figs. 455, 456); embolus rather thick, abruptly reflexed at tip (Figs. 455, 457); conductor rather large, flat, with hooked

Map 54. Collection localities of Araneus diadematus.

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Figs. 451–456. Araneus diadematus. 451, abdomen of female, dorsal view; 452–454, epigynum: 452, ventral view; 453, lateral view; 454, posterior view; 455–457, palpus of male: 455, mesal view; 456, ventral view; 457, embolus. ma, median apophysis; term, terminal apophysis.

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process; terminal apophysis bulbous at base, slender and pointed distally (Fig. 456). Female. Total length 15.61 ± 3.48 mm; carapace 5.92 ± 0.94 mm long, 5.01 ± 0.93 mm wide (10 specimens measured). Coloration much as in male but often darker; abdomen with anterolateral humps (Fig. 451); venter with median black band and paired white spots. Epigynum with long scape; scape reflexed near base, straight in ventral view (Fig. 452), spoon-shaped at tip (Figs. 452, 453); posterior sclerite triangular, without depressions or grooves (Fig. 454). Range. Michigan to Newfoundland; British Columbia, western Washington and Oregon; Europe and Asia. The spider is assumed, because of its first occurrence near ports, to be introduced in North America; in support of this is the fact that the species was not known to Emerton (1902). The oldest specimens in the Canadian National Collection are from Québec City, Quebec, and St. John’s, Newfoundland in 1919; the label with a Newfoundland specimen of 1924 reads: “European species known in Newfoundland since 1880.” Pickard-Cambridge (1881) identified a male and female from Brigus, Newfoundland. Comments. Specimens of A. diadematus are distinguished from those of other species of Araneus by the reflexed embolus, by the triangular posterior plate of the epigynum, and by the cross-shaped pattern of white spots on the abdomen. Biology. Individuals of A. diadematus build large orb webs in shrubs and trees around buildings, and seem to thrive in urban parks and gardens. Colebourn (1974) gives further habitat information. The web has about 30 radii, and the catching area may measure 30 cm in diameter. A silk-lined retreat is built in nearby foliage, though the spider may remain at the hub all day under certain conditions. Adults appear in late summer and autumn, and spend the winter in either the egg or juvenile stage, depending on latitude. In Germany (Wiehle 1931), emergence from the cocoon occurs in May, and the spiderlings build tiny orb webs of some 25 mm diameter. By the end of August they have a body length of 3–5 mm, and in this stage they overwinter among dead leaves or in bark crevices. In the following spring and summer they build webs that are successively larger until maturity is reached about the beginning of August. Male maturity precedes that of female by several days, and both sexes can be found until mid-September or later. Occasional individuals emerge and reach maturity in a single summer. Mature females lay their eggs before winter, though some individuals may overwinter in the unmated condition. The egg sac is constructed in some protected place away from the web; the eggs, numbering 100–800 in a sac, are yellow, and the outer covering golden yellowish. Various aspects of web economy are given by Breed et al. (1964), Smith and Mommsen (1984), Peters (1990), Rhisiart and Vollrath (1994), and Krink and Vollrath (1997). Courtship and mating are

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described by Blanke (1973, 1986). Head (1995) provides data supporting a relationship between male and female size variation.

Araneus nordmanni (Thorell) Figs. 458–465; Map 55

Epeira nordmanni Thorell, 1870:4; Emerton 1885:301, fig. 6 (pl. 33); 1894:403, fig. 2 (pl. 1). Epeira sylvatica Emerton, 1885:300, figs. 13 (pl. 33), 1, 4 (pl. 13). Aranea nordmanni: Wiehle 1931:58, figs. 84, 85; Kaston 1948:250, figs. 783, 784 (pl. 37), 793–795 (pl. 38). Aranea darlingtoni Archer, 1951:25, figs. 71, 75. Aranea pseudomalaena Archer, 1951:26, figs. 70, 79. Araneus nordmanni: Bonnet 1955:553; Levi 1971:151, figs. 61–94, 96–99.

Map 55. Collection localities of Araneus nordmanni.

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Figs. 458–465. Araneus nordmanni. 458, 459, abdomen of female, dorsal views; 460–462, epigynum: 460, ventral view; 461, lateral view; 462, posterior view; 463–465, palpus of male: 463, mesal view; 464, ventral view; 465, embolus. bla, basal lamella; el, embolar lamella; ma, median apophysis; pp, posterior plate; s, scape; term, terminal apophysis.

Male. Total length 7.33 ± 0.86 mm; carapace 3.88 ± 0.37 mm long, 3.14 ± 0.32 mm wide (10 specimens measured). Carapace gray or pale brown. Legs brown, with dark rings at middle and tip of segments; coxa I with hook; tibia II thick, angled, and with many stout macrosetae; coxa II with spur. Abdomen gray to nearly black, with dark oblique marks posteriorly (Figs. 458, 459); venter with comma-shaped white marks or with 2 pairs of white or yellow spots. Palpus with compact genital bulb; median apophysis with 1 basal and 1 distal spur (Figs. 463,

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464); embolus variable, but usually fingerlike and with prominent lamella at base (Figs. 463, 465); conductor large, flat, shallowly bilobed (Figs. 463, 464); terminal apophysis long, curved, pronglike, usually broad and flat at tip (Figs. 463, 464); subterminal apophysis long, rather slender, blunt. Female. Total length 11.26 ± 1.99 mm; carapace 4.17 ± 0.66 mm long, 3.46 ± 0.52 mm wide (10 specimens measured). Coloration much as in male, but abdominal pattern more distinct (Figs. 458, 459). Epigynum with long scape; scape with many transverse ridges and grooves, angled near base and near tip (Figs. 460, 461); posterior plate small, vase-shaped or elongate heart-shaped (Fig. 462); basal lamellae small, angular (Fig. 462). Range. Alaska to Newfoundland, south to Arizona, southern Texas, and South Carolina; Europe, Asia. Comments. Individuals of A. nordmanni are distinguished from those of other species in the genus by the fingerlike embolus, which has a lamella, by the shallowly bilobed conductor, and by the vase-shaped or elongate heart-shaped posterior plate of the epigynum. Biology. The usual habitat is on coniferous trees, at elevations up to 2200 m.

Araneus marmoreus Clerck Marbled Orbweaver Figs. 466–474; Map 56

Araneus marmoreus Clerck, 1758:29, fig. 2 (pl. 1); Locket and Millidge 1953:130, figs. 79d, 84c, 85c, 86c, 87b; Levi 1971:156, figs. 1–6, 100–105, 107–113, 183; Roberts 1985:208, fig. 93c. Aranea raji Scopoli, 1763:394; Wiehle 1931:75, figs. 109–114. Epeira insularis Hentz, 1847:470, fig. 10 (pl. 30); Emerton 1885:309, figs. 1 (pl. 33), 18 (pl. 35). Epeira obesa Hentz, 1847:471, fig. 11 (pl. 30). Epeira marmorea: Emerton 1885:307, fig. 2 (pl. 33), 17 (pl. 35). Aranea tusigia Chamberlin, 1919a:254, fig. 3 (pl. 19). Epeira raji: Kaston 1948:257, figs. 816–818, 820–822 (pl. 39), 2048, 2049 (pl. 125). Male. Total length 6.98 ± 1.90 mm; carapace 3.74 ± 0.93 mm long, 3.05 ± 0.72 mm wide (10 specimens measured). Carapace dull yellow or light brown, somewhat darker at midline and at lateral margins. Legs with segments white, darker at tips; coxa I with hook; coxa II with spur; tibia II thickened, with many short stout macrosetae on prolateral surface. Abdomen elliptical in outline, lacking humps; dorsum yellow, orange, or white, with pattern of brown or purplish

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Figs. 466–474. Araneus marmoreus. 466–468, abdomen of female, dorsal views; 469–471, epigynum: 469, ventral view; 470, lateral view; 471, posterior view; 472–474, palpus of male: 472, mesal view; 473, ventral view; 474, embolus. bla, basal lamella; ma, median apophysis; pp, posterior plate; term, terminal apophysis.

markings; venter brown, with paired semi-circular white spots. Palpus with genital bulb compact; median apophysis moderately large, with spur at base and with 2 blunt spurs at distal end (Figs. 472, 473); embolus broad, with nipplelike tip and slender lamella (Fig. 474), in unmated individuals with cap; conductor large, with uneven surface, and with curved basal margin; terminal apophysis long, stout, pointed, with semicircular curve (Figs. 472, 473). 222

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Map 56. Collection localities of Araneus marmoreus.

Female. Total length 11.92 ± 1.96 mm; carapace 4.32 ± 0.76 mm long, 3.93 ± 0.80 mm wide (10 specimens measured). Coloration much as in male, but abdominal pattern variable (Figs. 466–468); legs with femora and patellae orange, distal segments white, dark distally. Epigynum with moderately long scape; scape straight in ventral view, sinuous in lateral view, with many transverse grooves and ridges (Figs. 469, 470); posterior plate approximately triangular, with ventral angles finely pointed (Fig. 471); basal lamellae large, triangular, extending beyond ventral surface of epigynum (posterior view, Fig. 471). Range. Alaska to Newfoundland, south to Oregon, Utah, southern Texas, and South Carolina; Europe, Asia. Comments. Specimens of A. marmoreus are distinguished from those of other species of Araneus by the elliptical brightly colored abdomen, by the broad embolus, which has a nipplelike tip and a long slender lamella, and by the large triangular basal lamellae of the epigynum. Biology. Individuals of A. marmoreus frequent tall grass and shrubs in meadows and marshes, but are sometimes found in open forests. The web is nearly vertical, has 25–30 radii, and the spider builds a retreat and signal thread. Males are 223

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mature from late July to October, females from August to November. Blanke (1986) described courtship and mating. Tyshchenko and Marusik (1985) report web variation in northeast Asia. Eggs are laid in October (Kaston 1948). Wiehle (1931) collected specimens from fir and pine trees at heights of 50–80 cm above the ground; he inferred these individuals to have matured in a single summer after they overwintered as tiny hatchlings in the egg sac.

Araneus saevus (L. Koch) Figs. 475–481; Map 57

Epeira saeva L. Koch, 1872b:323. Epeira solitaria Emerton, 1885:299, figs. 11 (pl. 33), 3 (pl. 35). Epeira sylvatica: Emerton 1885:300, figs. 1–6 (pl. 35). Epeira nigra Emerton, 1894:402, fig. 1 (pl. 1). Aranea solitaria: Kaston, 1948:250, figs. 785, 786 (pl. 37), 796, 797 (pl. 38). Araneus saevus: Tullgren 1952:164, figs. 10, 12; Levi 1971:148, figs. 7, 8, 42–51, 55–60. Male. Total length 11.98 ± 1.92 mm; carapace 6.53 ± 0.97 mm long, 5.43 ± 0.88 mm wide (10 specimens measured). Carapace dark brown to black, with silvery setae. Legs nearly black, with darker rings at middle and tips of segments; coxa I with hook; coxa II with spur; tibia II thickened and armed with short stout macrosetae. Abdomen with paired humps anterolaterally, dark brown, usually

Map 57. Collection localities of Araneus saevus.

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Figs. 475–481. Araneus saevus. 475, abdomen of female, dorsal view; 476–478, epigynum: 476, ventral view; 477, lateral view; 478, posterior view; 479–481, palpus of male: 479, mesal view; 480, ventral view; 481, embolus. bla, basal lamella; con, conductor; ma, median apophysis; pp, posterior plate; term, terminal apophysis.

with white stripe anteriorly and with dark oblique marks posteriorly (Fig. 475); venter with paired white spots. Palpus with median apophysis and terminal apophysis prominent; median apophysis large, with spur near base and with large, broad rugose spur at distal end (Figs. 479, 480); embolus thick, with 3 or 4 blunt processes at tip (Fig. 481); conductor large, flat, rounded in outline, with 2 small 225

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basal processes (Fig. 480); terminal apophysis long, dark, curved in two planes (Figs. 479, 480). Female. Total length 11.65 ± 2.28 mm; carapace 4.78 ± 0.84 mm long, 4.24 ± 0.83 mm wide (10 specimens measured). Coloration much as in male, but abdominal pattern more distinct (Fig. 475). Epigynum with long scape; scape broad at base, more slender distally, straight or somewhat crooked in ventral view (Fig. 476), abruptly bent near base, somewhat sinuous distally (Fig. 477); posterior plate flat, bilobed (Fig. 478). Range. Alaska to Newfoundland, south to Oregon, northern Colorado, and New York; Europe, Asia. Comments. Specimens of A. saevus are distinguished from those of other species of Araneus by the prominent strongly curved terminal apophysis, by the thick embolus, which terminates in 3 or 4 blunt processes, and by the flat bilobed posterior plate of the epigynum. Large size is partly diagnostic. Biology. The usual habitat is the trunks and lower branches of large forest trees. Mature males and females have been collected in August and September.

Araneus corticarius (Emerton) Figs. 482–488; Map 58

Epeira corticaria Emerton, 1885:300, figs. 14 (pl. 33), 9 (pl. 35). Epeira incestifica Keyserling, 1892:132, fig. 98 (pl. 7). Aranea corticaria: Kaston 1948:252, figs. 800–802 (pl. 38). Aranea denningi Archer, 1951:30, fig. 81. Araneus corticarius: Bonnet 1955:470; Levi 1971:158, figs. 114–122. Male. Total length 4.84 ± 0.35 mm; carapace 2.55 ± 0.12 mm long, 2.22 ± 0.30 mm wide (10 specimens measured). Carapace brownish anteriorly, paler posteriorly. Legs pale, with dark rings at middle and end of each segment; coxa I with hook; coxa II without spur; tibia II somewhat thickened, with several stout macrosetae on prolateral surface. Abdomen broad, with humps extending laterally, dark anteriorly with mesal white marks, paler posteriorly with oblique darker marks (Fig. 482). Palpus with sclerites protruding; median apophysis long, with long slender curved spur at base and with shorter broad spur distally (Figs. 486, 487); embolus broad, with small blunt tip, and with small lamella (Fig. 488); conductor large, thick, flaplike (Fig. 486); terminal apophysis short, slender, curved (Figs. 486, 487). Female. Total length 6.86 ± 0.62 mm; carapace 2.77 ± 0.29 mm long, 2.31 ± 0.17 mm wide (10 specimens measured). Coloration as in male but much more distinct. Abdominal humps extending prominently to sides (Fig. 482). Epigynum 226

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Figs. 482–488. Araneus corticarius. 482, abdomen of female, dorsal view; 483–485, epigynum: 483, ventral view; 484, lateral view; 485, posterior view; 486–488, palpus of male: 486, mesal view; 487, ventral view; 488, embolus. bla, basal lamella; con, conductor; ma, median apophysis; pp, posterior plate; term, terminal apophysis.

with short scape; scape broad at base, tapered toward tip, with numerous transverse grooves and ridges, nearly straight in ventral view (Fig. 483), strongly sinuous in lateral view (Fig. 484), sometimes lost; posterior plate V-shaped (Fig. 485); basal lamellae slender (Fig. 485). Range. Alaska to Nova Scotia, south to northeastern North Dakota, southern Michigan, and northern Pennsylvania. Hackman (1954) recorded specimens from three localities in Newfoundland. Levi (1971) notes the similarity of the range to that of black spruce and tamarack, both of which are regarded as typical bog trees. 227

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Map 58. Collection localities of Araneus corticarius.

Comments. Specimens of A. corticarius are distinguished from those of other species in the genus by the large abdominal humps and contrasting dorsal pattern, by the long median apophysis, by the thick flaplike conductor, and by the V-shaped posterior plate and slender basal lamellae of the epigynum. Biology. Swamps and bogs appear to be the principal habitat for individuals of A. corticarius. Kaston (1948) notes August as the time of maturity.

Araneus washingtoni Levi Figs. 489–495; Map 59

Araneus washingtoni Levi, 1971:160, figs. 123–130. Male. Total length 4.77 ± 0.46 mm; carapace 2.56 ± 0.44 mm long, 1.47 ± 0.14 mm wide (10 specimens measured). Carapace brown. Legs light brown basally, darker distally, with indistinct darker rings; coxa I with hook; coxa II without spur; tibia II stout, with several stout macrosetae. Abdomen with antero228

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Figs. 489–495. Araneus washingtoni. 489, abdomen of female, dorsal view; 490–492, epigynum: 490, ventral view; 491, lateral view; 492, posterior view; 493–495, palpus of male: 493, mesal view; 494, ventral view; 495, embolus. bla, basal lamella; con, conductor; ma, median apophysis; term, terminal apophysis.

lateral humps, brownish, with off-white mesal marks anteriorly, and with dark patch posteriorly. Palpus with genital bulb compact; median apophysis rather large, with slender curved spur at base, and with broad truncate spur at distal end (Figs. 493, 494); embolus thick, with small curved tip, with or without cap (Fig. 495); conductor large, flat, with 2 small basal processes (Fig. 493); terminal apophysis short, slender, curved (Figs. 493, 494). Female. Total length 6.00 (4.60–7.60) mm; carapace 2.95 (2.16–3.96) mm long, 2.20 (1.99–2.50) mm wide (5 specimens measured). Coloration as in male but much more distinct (Fig. 489); venter of abdomen black, with paired white 229

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Map 59. Collection localities of Araneus washingtoni.

bracket-shaped bands. Epigynum with short scape; scape crooked in ventral view (Fig. 490), abruptly angled in lateral view (Fig. 491), with several shallow grooves and ridges; posterior plate V-shaped (Fig. 492); basal lamellae rather large, angular (Fig. 492). Range. Northern British Columbia to Newfoundland, south to Mt. Washington, New Hampshire; northeast Asia. Comments. Specimens of A. washingtoni are distinguished from those of other species in the genus by the large flat conductor, which has 2 small basal processes, and by the abruptly angled scape (lateral view), V-shaped posterior plate, and moderately large angular basal lamellae. Biology. The habitat is coniferous forest. Webs have been found on balsam fir or low shrubs in the boreal forest zone.

Araneus groenlandicola (Strand) Figs. 496–502; Map 60

Aranea reaumuri var. groenlandicola Strand, 1906:458. Aranea manitobae Archer, 1951:37, figs. 51, 59, 62. Araneus groenlandicolus: Levi 1971:164, figs. 159–166. 230

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Figs. 496–502. Araneus groenlandicola. 496, abdomen of female, dorsal view; 497–499, epigynum: 497, ventral view; 498, lateral view; 499, posterior view; 500–502, palpus of male: 500, mesal view; 501, ventral view; 502, embolus. bla, basal lamella; con, conductor; ma, median apophysis; pp, posterior plate; term, terminal apophysis.

Araneus groenlandicola: Levi 1973:480. Male. Total length 5.93 ± 0.42 mm; carapace 3.15 ± 0.25 mm long, 2.66 ± 0.14 mm wide (10 specimens measured). Carapace light brown. Legs light brown, with indistinct darker rings; coxa I without hook; coxa II without spur; tibia II thickened, with several stout macrosetae. Abdomen off-white. Palpus compact except for projecting median apophysis on ventral surface of genital 231

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Map 60. Collection localities of Araneus groenlandicola.

bulb; median apophysis large, with short stout spur at base and with 2 long curved spurs at distal end (Figs. 500, 501); embolus broad at base, tapering to sharp point, with small basal lamella (Fig. 502); conductor large, flat, approximately rectangular (Fig. 500); terminal apophysis small, bulbous (Figs. 500, 501). Female. Total length 8.79 ± 1.80 mm; carapace 3.27 ± 0.39 mm long, 3.20 ± 0.58 mm wide (10 specimens measured). Carapace light brown, with dark median and submarginal bands. Legs with distinct dark rings. Abdomen without humps, off-white, or reddish and with several paired or median white marks (Fig. 496). Epigynum with short broad scape; scape broad at base, tapered to blunt tip, acutely angled near base (lateral view, Fig. 498), with many shallow ridges and grooves (Figs. 497, 498); posterior plate approximately Y-shaped (Fig. 499). Range. Alberta to Newfoundland and Nova Scotia, south to Minnesota and Maine; Greenland. Comments. Specimens of A. groenlandicola are distinguished from those of other species of Araneus by the 2 long curved distal spurs on the median apophysis, by the small bulbous terminal apophysis, and by the short basally broad scape and Y-shaped posterior plate of the epigynum. Biology. Individuals of A. groenlandicola build their orb webs among low shrubs on bogs and arctic tundra. 232

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Araneus trifolium (Hentz) Shamrock Orbweaver Figs. 503–509; Map 61

Epeira trifolium Hentz, 1847:471, fig. 1 (pl. 31); Emerton 1885:306, figs. 8 (pl. 33), 13, 14, 21, 22 (pl. 35); Kaston 1948:258, figs. 823–825 (pl. 39), 2047 (pl. 124). Epeira aureola Hentz, 1847:471, fig. 2 (pl. 31). Aranea gosogana Chamberlin, 1919b:8, fig. 6 (pl. 4). Araneus trifolium: Bonnet 1955:614; Levi 1971:167, figs. 174–182. Male. Total length 5.31 ± 0.56 mm; carapace 3.00 ± 0.38 mm long, 2.36 ± 0.17 mm wide (10 specimens measured). Carapace white to brown. Legs brown, with indistinct darker rings; coxa I without hook; coxa II without spur; tibia II somewhat thicker than other leg tibiae, with few stout macrosetae. Abdomen offwhite. Palpus with compact genital bulb; median apophysis small, with 1 slender

Map 61. Collection localities of Araneus trifolium.

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Figs. 503–509. Araneus trifolium. 503, abdomen of female, dorsal view; 504–506, epigynum: 504, ventral view; 505, lateral view; 506, posterior view; 507–509, palpus of male: 507, mesal view; 508, ventral view; 509, embolus. bla, basal lamella; con, conductor; el, embolar lamella; ma, median apophysis; term, terminal apophysis.

spur at base and with 1 or 2 short spurs at distal end (Figs. 507, 508); embolus broad, with short tip, and with large hooked basal lamella (Fig. 509); conductor approximately triangular (Fig. 508); terminal apophysis long, flat, rounded at tip (Figs. 507, 508). Female. Total length 10.61 ± 2.06 mm; carapace 4.66 ± 0.99 mm long, 4.06 ± 0.85 mm wide (10 specimens measured). Carapace off-white, with dark median longitudinal stripe and with dark marginal stripes. Legs white to yellow,

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with conspicuous dark rings. Abdomen off-white, reddish or purplish, sometimes greenish; colored specimens usually with paired and unpaired angular white spots (Fig. 503); venter dark, usually unmarked. Epigynum with short scape, and with large lateral cavities (Fig. 504); scape sinuous in lateral view (Fig. 505), with free part parallel at sides, and with few indistinct ridges and grooves; posterior plate small, V-shaped (Fig. 506). Range. Alaska to Newfoundland, south to California, New Mexico, and Alabama. Comments. Specimens of A. trifolium are distinguished from other species of Araneus by the triangular conductor, large hooked basal lamella on the embolus, by the parallel sides of the epigynal scape, and by the large lateral cavities of the epigynum. Females are among the largest spiders of the genus in Canada. Biology. Individuals of A. trifolium build large orb webs in shrubs and in tall herbs such as goldenrod. Horton (1979) thought the web to be attractive in some way to adult males of the northern buckmoth. The web has about 20 radii, and there is a silk-lined retreat among leaves and a signal thread (Kaston 1948). Maturity is from August to October. Kaston (1977) counted 2,652 eggs in a single egg sac: he believed this to be the largest number ever reported for any spider.

Araneus yukon Levi Figs. 510–516; Map 62

Araneus yukon Levi, 1971:166, figs. 167–173. Male. Total length 6.64 (6.50–6.85) mm; carapace 3.74 (3.40–3.86) mm long, 3.09 (2.84–3.36) mm wide (4 specimens measured). Carapace brown, with indistinct median and lateral markings. Legs brown, with indistinct darker rings; coxa I without hook; coxa II without spur; tibia II somewhat stouter than other leg tibiae. Abdomen brownish, with median longitudinal white mark anteriorly, and with two pairs of white spots. Palpus with sclerites protruding mesally and ventrally; median apophysis large, with slender curved spur at base, and with long slender spur and broader shorter toothed spur distally (Figs. 514, 515); embolus long, slender, sinuous, with long conical basal lamella (Fig. 516); conductor large, flat, rectangular; terminal apophysis flaplike (Figs. 514, 515). Female. Total length 9.19, 10.00 mm; carapace 3.80, 4.20 mm long, 3.50, 3.56 mm wide (2 specimens measured). Coloration as in male, but leg rings and dorsal abdominal pattern more distinct (Fig. 510). Epigynum with short scape; scape broad at base, tapered to blunt tip, sinuous in lateral view, with many fine ridges and grooves, flanked by elongate cavities (Figs. 511, 512); posterior plate slender, V-shaped (Fig. 513); basal lamellae elongate, slender (Fig. 513).

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Figs. 510–516. Araneus yukon. 510, abdomen of female, dorsal view; 511–513, epigynum: 511, ventral view; 512, lateral view; 513, posterior view; 514–516, palpus of male: 514, mesal view; 515, ventral view; 516, embolus. bla, basal lamella; con, conductor; el, embolar lamella; ma, median apophysis; term, terminal apophysis.

Range. Yukon Territory and western Northwest Territories; northeast Asia. Comments. Specimens of A. yukon are distinguished from those of other species of Araneus by the long slender sinuous tip and long conical basal lamella on the embolus, and by the elongate cavities flanking the epigynal scape. Levi (1971) notes the close similarity between specimens of A. yukon and of the European A. quadratus Clerck, and gives distinguishing characters. Biology. No precise data are available.

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Map 62. Collection localities of Araneus yukon.

Araneus pratensis (Emerton) Figs. 517–523; Map 63

Singa pratensis Emerton, 1885:322, figs. 15 (pl.34), 14, 15 (pl. 37); Kaston 1948:240, figs. 745 (pl. 35), 758 (pl. 36); Kaston 1977:30, figs. 23, 24. Epeira reptilis Keyserling, 1893:244, fig. 182 (pl. 12). Singa listerii McCook, 1894:231, figs. 3, 4 (pl. 19). Araneus praticola Simon, 1895:807. New name for Epeira pratensis Emerton, thought preoccupied. Araneus pratensis: Levi 1973:492, plate 3, figs. 2, 21–31; 1975:270. Male. Total length 3.27 (3.10–3.60) mm; carapace 1.67 (1.53–1.77) mm long, 1.32 (1.14–1.40) mm wide (4 specimens measured). Carapace yellowish, sometimes with darker mesal and lateral stripes, with eye area black, without setae. Legs yellowish, without dark rings; coxa I without hook; coxa II without spur; tibia II somewhat thickened and curved. Abdomen elliptical, without setae, with indistinct mesal stripe and with paired distinct lateral stripes; lateral stripes sometimes flanked by longitudinal row of small black spots; venter dark, with paired yellowish marks. Palpus with compact genital bulb; median apophysis large, nearly as long as genital bulb, oriented longitudinally (Figs. 522, 523);

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Figs. 517–523. Araneus pratensis. 517, female, dorsal view; 518–520, epigynum: 518, posterior view; 519, ventral view; 520, lateral view; 521, spermathecae; 522, 523, palpus of male: 522, mesal view; 523, ventral view. e, embolus; ma, median apophysis; spt, spermatheca; term, terminal apophysis.

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Map 63. Collection localities of Araneus pratensis.

embolus fingerlike (Fig. 522); conductor small, flat; terminal apophysis thick, broad, blunt (Figs. 522, 523). Female. Total length 4.38 (3.98–4.90) mm; carapace 1.91 (1.83–2.00) mm long, 1.41 (1.37–1.44) mm wide (4 specimens measured). Coloration as in male (Fig. 517). Epigynum with short variable scape; scape approximately triangular or approximately rectangular in outline, with indistinct ridges and grooves, with few setae (Figs. 519, 520), with basal bend (lateral view, Fig. 520), sometimes missing (Fig. 518); posterior plate poorly defined, approximately rectangular (Fig. 518); spermathecae ovoid (Fig. 521). Range. Iowa and southern Ontario to northern New Hampshire, south to Texas and Florida. Comments. Specimens of A. pratensis are distinguished from those of other species of Araneus by the large longitudinally oriented median apophysis, by the poorly defined rectangular posterior plate of the epigynum, by the smooth body, and by the paired dark longitudinal stripes on the abdomen. Specimens of A. pratensis are among the smaller representatives of the genus. 239

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Biology. The common habitats are fields, meadows, and forage crops. The web is about 20 cm in diameter. The spider is nocturnal and builds no retreat (Kaston 1948, Levi 1973). According to Kaston (1948), individuals winter as adults and persist until mid-June.

Araneus iviei (Archer) Figs. 524–530; Map 64

Aranea iviei Archer, 1951:33, fig. 53. Aranea sachimau Archer, 1951:33, fig. 55. Araneus iviei: Levi 1971:162, figs. 138–151; 1973:481. Male. Total length 6.25 ± 0.75 mm; carapace 3.24 ± 0.35 mm long, 2.69 ± 0.24 mm wide (10 specimens measured). Carapace brown or brownish orange, without darker stripes. Legs brown or brownish orange, sometimes with indistinct darker rings; coxa I without hook; coxa II without spur; tibia II not expanded. Abdomen off-white, with indistinct oblique black marks posteriorly; venter dark, with off-white median spot. Palpus with compact genital bulb; median apophysis small, with 1 slender spur at base and a somewhat stouter one distally (Figs. 528, 529); embolus thick, with blunt tip, and with small conical lamella (Fig. 530), sometimes with cap; conductor subdivided, approximately ovoid in outline (Fig. 529); terminal apophysis long, angled near middle, slender and curved distally (Figs. 528, 529). Female. Total length 9.31 ± 1.77 mm; carapace 3.77 ± 0.47 mm long, 3.31 ± 0.40 mm wide (9 specimens measured). Coloration much as in male, but abdomen with many off-white angular spots (Fig. 524). Epigynum with rather short scape; scape moderately wide, approximately uniform in width, essentially straight in ventral view (Fig. 525), somewhat sinuous in lateral view (Fig. 526),

Map 64. Collection localities of Araneus iviei.

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Figs. 524–530. Araneus iviei. 524, abdomen of female, dorsal view; 525–527, epigynum: 525, ventral view; 526, lateral view; 527, posterior view; 528, 529, palpus of male: 528, mesal view; 529, ventral view. bla, basal lamella; con, conductor; ma, median apophysis; pp, posterior plate; term, terminal apophysis.

with many transverse ridges and grooves; posterior plate elongate, V-shaped, with small round copulatory openings at ventral end (Fig. 527); basal lamellae elongate, comma-shaped (Fig. 527). Range. British Columbia to Nova Scotia, south to Michigan and eastern Pennsylvania. 241

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Comments. Specimens of A. iviei are distinguished from those of other North American species of Araneus by the subdivided ovoid conductor of the male palpus, and by the distinct round copulatory openings and comma-shaped basal lamellae of the epigynum. Biology. The habitats are swamps, abandoned fields, and coniferous forests.

Araneus alboventris (Emerton) Figs. 531–538; Map 65

Epeira alboventris Emerton, 1885:314, figs. 5 (pl. 34), 12 (pl. 36). Araneus attestor Petrunkevitch, 1911:280. Unnecessary new name for Epeira alboventris. Epeira attestor: Kaston 1948:260, figs. 791, 792 (pl. 37). Conepeira alboventris: Archer 1951:20, figs. 47, 71. Araneus alboventris: Levi 1973:514, plate 6, figs. 192–203. Male. Total length 2.0 mm; carapace 1.30 mm long, 1.00 mm wide (1 specimen measured). Carapace yellow or greenish yellow. Legs yellow or greenish

Map 65. Collection localities of Araneus alboventris.

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Figs. 531–538. Araneus alboventris. 531, female, dorsal view; 532, abdomen of female, dorsal view; 533, 534, epigynum: 533, ventral view; 534, posterior view; 535, spermathecae; 536–538, palpus of male: 536, mesal view; 537, ventral view; 538, embolus. con, conductor; ma, median apophysis; pp, posterior plate; term, terminal apophysis.

yellow, without dark rings; coxa I without hook; coxa II without spur; tibia II not expanded. Abdomen triangular, yellowish or off-white, usually with large triangular black patch (Figs. 531, 532); patch often bordered with red. Palpus with compact genital bulb; median apophysis small, with large curved tooth at base, and with smaller distal tooth (Figs. 536, 537); embolus in tight curl (Fig. 538); conductor small, semicircular in outline, with long slender spur (Fig. 536); ter243

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minal apophysis strongly sclerotized, broad at base, with slender distal part (Figs. 536, 537). Female. Total length 5.18 mm; carapace 2.08 mm long, 1.83 mm wide (1 specimen measured). Coloration as in male (Figs. 531, 532). Epigynum with short scape; scape bulbous, broad and blunt at tip, with few transverse grooves, flanked by large openings (Fig. 533); posterior plate large, vase-shaped (Fig. 534); spermathecae round in ventral view, elongate in posterior view (Fig. 535), nearly touching. Range. Maine, south to northern Georgia. Comments. Specimens of A. alboventris are distinguished from those of other species of Araneus by the triangular black patch on the abdomen, and by the tightly curled embolus, long basal spur on the median apophysis, and semicircular conductor of the male palpus. Biology. The habitats are in meadow shrubs (Levi 1973). Kaston (1948) gives maturity time for females as the month of June.

Araneus cavaticus (Keyserling) Figs. 539–545; Map 66

Epeira cavatica Keyserling, 1882:269, fig. 1 (pl. 11). Epeira cinerea Emerton, 1885:302, figs. 10 (pl. 33), 7, 8 (pl. 35). Aranea cavatica: Kaston 1948:251, figs. 798, 799 (pl. 38). Araneus cavaticus: Bonnet 1955:453; Levi 1971:170, plate 2, figs. 187–194. Male. Total length 12.75 ± 2.04 mm; carapace 6.72 ± 1.42 mm long, 4.81 ± 1.17 mm wide (10 specimens measured). Carapace yellowish brown, sometimes darker anteriorly. Legs yellowish brown, with darker rings, hairy and with numerous long slender macrosetae; coxa I without hook; coxa II without spur; tibia II not thickened nor provided with stout macrosetae. Abdomen ovoid in outline, with paired anterolateral humps, hairy, gray, grayish brown, bluish, or brown, with oblique darker markings; venter dark mesally, with paired curved white or yellow lateral marks. Palpus compact; median apophysis small, with small slender spur at base, and with smaller spur distally (Figs. 543, 544); embolus curved uniformly, slender distally, with small lamella (Fig. 545); conductor rounded in outline (Fig. 544); terminal apophysis broad at base, more slender distally (Figs. 543, 544). Female. Total length 16.85 ± 1.90 mm; carapace 6.59 ± 0.47 mm long, 5.62 ± 0.43 mm wide (10 specimens measured). Coloration as in male (Fig. 539). Epigynum with short scape; scape broad at base, tapered to blunt tip, angled near

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Figs. 539–545. Araneus cavaticus. 539, abdomen of female, dorsal view; 540–542, epigynum: 540, ventral view; 541, lateral view; 542, posterior view; 543–545, palpus of male: 543, mesal view; 544, ventral view; 545, embolus. bla, basal lamella; con, conductor; ma, median apophysis; pp, posterior plate; term, terminal apophysis.

base, with many shallow grooves (Figs. 540, 541); posterior plate flat, triangular, with ventral angles pointed (Fig. 542); basal lamellae fan-shaped (Fig. 542). Range. Southern Ontario to Nova Scotia, south to Texas and northern Alabama.

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Map 66. Collection localities of Araneus cavaticus.

Comments. Specimens of A. cavaticus are distinguished from those of other species of Araneus by the distinctly hairy body and legs, grayish coloration, curved and uniformly slender distal part of the embolus, and basally broad epigynal scape. Individuals of A. cavaticus are among the largest of the northern representatives of the genus. Biology. Individuals of A. cavaticus have been collected on and inside barns, porches, and sheds, under bridges, on cliffs, and in ravines. The web is large, has about 20 radii and more than 20 spiral threads (Levi 1971). There may or may not be a retreat and signal thread, according to the individual. Kaston (1948) gives early July as the beginning of the maturity period.

Araneus gemmoides Chamberlin & Ivie Figs. 546–552; Map 67

Epeira gemma: Keyserling 1892:115, fig. 85 (pl. 6). Misidentification.

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Figs. 546–552. Araneus gemmoides. 546, abdomen of female, dorsal view; 547–549, epigynum: 547, ventral view; 548, lateral view; 549, posterior view; 550–552, palpus of male: 550, mesal view; 551, ventral view; 552, embolus. con, conductor; e, embolus; ma, median apophysis; pp, posterior plate; term, terminal apophysis.

Araneus gemmoides Chamberlin and Ivie, 1935:22, fig. 80 (pl. 10); Levi 1971:171, plate 2, figs. 195–202. Araneus canmorus Schenkel, 1950:65.

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Map 67. Collection localities of Araneus gemmoides.

Male. Total length 7.35 (6.68–7.52) mm; carapace 3.97 (3.34–4.50) mm long, 2.93 (2.34–3.50) mm wide (4 specimens measured). Carapace pale brown. Legs yellowish brown, with indistinct darker rings; coxa I without hook; coxa II without spur; tibia II not enlarged, without stout macrosetae. Abdomen brownish, sometimes with indistinct paired oblique marks posteriorly, with distinct anterodorsal humps (Fig. 546). Palpus with small compact genital bulb; median apophysis small, with basal and distal spurs of nearly equal length and thickness (Figs. 550, 551); embolus broad at base, with minute slender tip, sometimes with cap (Fig. 552); conductor small, flat, angular (Fig. 550); terminal apophysis broad basally, slender and curved distally (Figs. 550, 551). Female. Total length 14.89 ± 3.11 mm; carapace 6.29 ± 0.71 mm long, 5.21 ± 0.67 mm wide (10 specimens measured). Coloration as in male (Fig. 546). Epigynum approximately triangular; scape blunt at tip, with thick lateral margins, and with few shallow grooves (Figs. 547, 548); posterior plate Y-shaped, with arms of Y angulate (Fig. 549); basal lamellae minute (Fig. 549).

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Range. Southern British Columbia to southern Manitoba and Michigan, south to Baja California and northern Florida. Comments. Specimens of A. gemmoides are distinguished from those of other species of Araneus by the small genital bulb, by the triangular epigynum, and by the angled arms of the Y-shaped posterior plate of the epigynum. Biology. Individuals of A. gemmoides have been collected on barns and other outbuildings, under rock ledges, and in lodgepole pine forests. The web is large, having about 20 radii (Levi 1971).

Araneus gemma (McCook) Figs. 553–559; Map 68

Epeira gemma McCook, 1888:193, figs. 1, 2. Araneus gemmus: Chamberlin and Ivie 1935:21, fig. 79 (pl. 10). Araneus pirus Chamberlin and Ivie, 1935:22, fig. 81 (pl. 10). Araneus gemma: Bonnet 1955:506; Levi 1971:172, figs. 203–215. Male. Total length 6.18, 8.00 mm; carapace 3.51, 4.20 mm long, 3.01, 3.30 mm wide (2 specimens measured). Carapace yellowish brown. Legs yellowish brown; coxa I without basal hook, with small distal spur; coxa II without spur; tibia II not enlarged, lacking stout macrosetae. Abdomen with anterolateral humps, brownish, sometimes with median off-white stripe anteriorly, and with few oblique dark marks posteriorly (Fig. 553); venter grayish, with white bracket-shaped marks. Palpus with compact genital bulb; median apophysis small, with basal and distal spurs nearly equal in size, little separated (Figs. 557, 558); embolus broad at base, abruptly tapered to fine tip, with distal margin concave (Fig. 559), sometimes with cap; conductor small, flat, rectangular (Figs. 557, 558); terminal apophysis small, broad at base, slender distally (Figs. 557, 558). Female. Total length 10.19, 12.00 mm; carapace 5.01, 5.30 mm long, 3.84, 4.60 mm wide (2 specimens measured). Coloration as in male (Fig. 553). Epigynum with short scape; scape broad, tapered to blunt tip, with mesal ridge, with thick lateral margins and with few shallow grooves (Figs. 554, 555), angled near tip; posterior plate small, narrow, V-shaped (Fig. 556); basal lamellae long, slender, diverging (Fig. 556). Range. Southernmost Alaska to southern California, inland to western Montana. Comments. Specimens of A. gemma are distinguished from those of other species of Araneus by the concave distal margin at the base of the embolus, and by the median ridge on the epigynal scape.

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Figs. 553–559. Araneus gemma. 553, abdomen of female, dorsal view; 554–556, epigynum: 554, 555, ventral views; 556, posterior view; 557–559, palpus of male: 557, mesal view; 558, ventral view; 559, embolus. e, embolus; ma, median apophysis; term, terminal apophysis.

Biology. Individuals of A. gemma have been collected on porches and tree trunks (Levi 1971).

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Map 68. Collection localities of Araneus gemma.

Araneus montereyensis (Archer) Figs. 560–567; Map 69

Conaranea montereyensis Archer, 1951:8, figs. 3, 24, 25. Araneus montereyensis: Levi 1973:506, figs. 108, 109, 138–151. Male. Total length 4.23 mm; carapace 1.91 mm long, 1.66 mm wide (1 specimen measured). Carapace orange, sparsely covered with fine, pale, anteriorly directed setae. Legs yellowish or orange, with bases of femora I and II paler; tibia I with 4 pairs of long stout dark macrosetae, and tibia II with similar but shorter macrosetae. Abdomen approximately triangular, with low humps anterolaterally,

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Figs. 560–567. Araneus montereyensis. 560, female, dorsal view; 561, abdomen of female, dorsal view; 562, 563, epigynum: 562, ventral view; 563, posterior view; 564, spermathecae; 565–567, palpus of male: 565, mesal view; 566, ventral view; 567, embolus. con, conductor; ma, median apophysis; spt, spermatheca; term, terminal apophysis.

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Map 69. Collection localities of Araneus montereyensis.

off-white, with broad, reddish to black lateral areas anteriorly and with a dark red median band and oblique dark marks posteriorly; venter dull reddish to black, bordered with off-white longitudinal bands. Palpal patella with 2 macrosetae; median apophysis approximately triangular, with 2 strong spurs (Figs. 565, 566); distal spur of median apophysis sometimes with subsidiary teeth; conductor broad, with constriction at tip; embolus long, curved, with tip largely concealed in mesal view by conductor (Figs. 565, 567); terminal apophysis thick, dark, with blunt tip (Figs. 565, 566). Female. Total length 4.15, 4.40 mm; carapace 2.08, 2.08 mm long, 1.49, 1.66 mm wide (2 specimens measured). Coloration much as in male (Figs. 560, 561), 253

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but carapace and legs sometimes brownish; tibiae I and II with only 1 pair of stout macrosetae, these situated at tip of segment. Epigynum with short broad scape; scape straight or nearly so (Fig. 562); posterior plate small, pale, angular (Figs. 563, 564); spermathecae each of 2 small parts (Fig. 564). Range. Southernmost British Columbia to southern California. Comments. Males of A. montereyensis are distinguished from those of other species in the genus by the broad, distally constricted conductor. Females are distinguished by the small, pale, angular posterior plate of the epigynum. The presence of paired oblique marks on the abdominal dorsum is unusual among the small species of Araneus. Biology. Levi (1973) reported collections of A. montereyensis from chaparral and coastal oak woodland in California. The Canadian specimens were collected by malaise traps in the canopy of Douglas fir forest or on the forest floor. Males have been collected from early spring to mid-August, females from spring to early November.

Araneus juniperi (Emerton) Figs. 568–574; Map 70

Epeira juniperi Emerton, 1885:313, figs. 6 (pl. 34), 14–16 (pl. 36); Kaston 1948:261, figs. 811 (pl. 38), 830 (pl. 40). Singa floridana Banks, 1896a:69. Conepeira mumai Archer, 1951:22, fig. 51. Conepeira sarasota Archer, 1951:23, fig. 74. Conepeira llano Archer, 1951:24, figs. 52, 55. Araneus juniperi: Levi 1973:522, figs. 248–264, 447–452. Male. Total length 3.74, 3.80 mm; carapace 1.80, 2.34 mm long, 1.50, 1.84 mm wide (2 specimens measured). Carapace greenish or yellow. Legs greenish or yellow; coxa I without hook; coxa II without spur; tibia II not enlarged, lacking stout macrosetae. Abdomen ovoid in outline, greenish or yellowish, with 3 white longitudinal bands (Fig. 568); venter with broad white longitudinal band. Palpus with compact genital bulb; median apophysis long, protruding from mesal surface of bulb, with long tapered basal spur and with minute distal spur (Figs. 572, 573); embolus long, slender, gently hooked at tip (Figs. 572, 574); conductor bulbous, blunt, with small tooth on base (Figs. 572, 573); terminal apophysis broad, dark, rugose, shallowly concave at tip (Figs. 572, 573). Female. Total length 2.66, 5.20 mm; carapace 1.33, 1.90 mm long, 1.08, 1.50 mm wide (2 specimens measured). Coloration as in male (Fig. 568). Epigynum with short scape; scape angled, with broad spoonlike tip, and with few shallow grooves (Fig. 569); copulatory openings slitlike, narrow, oblique (Figs. 570, 571);

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Figs. 568–574. Araneus juniperi. 568, female, dorsal view; 569, 570, epigynum: 569, ventral view; 570, posterior view; 571, spermathecae; 572–574, palpus of male: 572, mesal view; 573, ventral view; 574, embolus. co, copulatory opening; con, conductor; ma, median apophysis; pp, posterior plate; term, terminal apophysis.

posterior plate vase-shaped (Fig. 570); spermathecae round in ventral view, kidney-shaped in posterior view (Fig. 571). Range. Illinois to Nova Scotia, south to Texas and Florida.

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Map 70. Collection localities of Araneus juniperi.

Comments. Specimens of A. juniperi are distinguished from those of other species of Araneus by the broad white stripes and green (in life) or yellowish (in preserved specimens) background, by the long slender gently curved embolus, and the slitlike oblique copulatory openings. Biology. Individuals of A. juniperi have been collected from the foliage of coniferous trees. According to Kaston (1948), maturity is from June to August.

Araneus cingulatus (Walckenaer) Figs. 575–582; Map 71

Epeira cingulata Walckenaer, 1841:40. Conepeira marilandica Archer, 1951:21, figs. 40, 50. Conepeira inominata Archer, 1951:24, fig. 62. Conepeira ozarkensis Archer, 1951:25, fig. 76. Araneus cingulatus: Levi 1973:526, plate 7, figs. 301–313, 455–462.

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Figs. 575–582. Araneus cingulatus. 575, 576, female, dorsal views; 577, 578, epigynum: 577, ventral view; 578, posterior view; 579, spermathecae; 580–582, palpus of male: 580, mesal view; 581, ventral view; 582, embolus. co, copulatory opening; con, conductor; e, embolus; ma, median apophysis; pp, posterior plate; term, terminal apophysis.

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Map 71. Collection localities of Araneus cingulatus.

Male. Total length 3.10 mm; carapace 1.60 mm long, 1.35 mm wide (1 specimen measured). Carapace yellowish green or yellowish. Legs yellowish green or yellowish, I and II brownish distally; coxa I without hook; coxa II without spur; tibia II not expanded nor provided with stout macrosetae. Abdomen ovoid, in life bright green, in preservative yellowish, with 4 or 5 pairs of small red spots laterally (Fig. 576); spots surrounded with yellow. Palpus with compact genital bulb; median apophysis protruding from mesal surface of bulb, long, with 1 long spur (Figs. 580, 581); embolus long, erect, curved throughout its length (but more so distally) (Fig. 582); conductor bulbous, boot-shaped, with small sharp tooth at base (Fig. 580); terminal apophysis broad, rugose, oblique at tip (Figs. 580, 581). Female. Total length 3.90 mm; carapace 1.83 mm long, 1.68 mm wide (1 specimen measured). Coloration as in male (Figs. 575, 576). Epigynum with short broad scape; scape tortuous, spoon-shaped at tip, with distinct lateral rim (Fig. 577); posterior plate vase-shaped, with ventral angles long, extended laterally (Fig. 578); spermathecae round in ventral view, dumbbell-shaped in posterior view (Fig. 579).

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Range. Missouri to northern New York and Massachusetts, south to Texas and Florida. Comments. Specimens of A. cingulatus are distinguished from those of other species of Araneus by the combination of long erect curved embolus and oblique terminal apophysis, and by the laterally extended tips of the posterior plate of the epigynum. The small paired red spots on the abdomen are partially diagnostic. Biology. Individuals of A. cingulatus build their webs in tall grass and in shrubs and trees (Coddington 1987). Certain wasps stock these individuals, as well as those of other “small Araneus”, in their mud cells as larval food, and collections can sometimes be made from such cells (Levi 1973).

Araneus guttulatus (Walckenaer) Figs. 583–592; Map 72

Epeira guttulata Walckenaer, 1841:78. Epeira sanguinalis Hentz, 1847:476, fig. 15 (pl. 31). Conepeira glyphica Archer, 1951:17, fig. 56. Araneus guttulatus: Levi 1973:530, plate 8, figs. 332–361, 470–474. Male. Total length 3.32 mm; carapace 1.86 mm long, 1.74 mm wide (1 specimen measured). Carapace yellowish. Legs yellow or greenish yellow; coxa I without hook; coxa II without spur; tibia II not expanded, without stout macrosetae. Abdomen with series of paired oblique reddish marks or with black triangular patch posteriorly, sometimes with dark transverse area anteriorly (Fig. 584); venter yellow or greenish yellow. Palpus with sclerites protruding; median apophysis short, thick, with long tapered spur (Figs. 591, 592); embolus long, slender, inclined, hooked at tip (Figs. 591, 592); conductor boot-shaped, with small, sharp, partly concealed tooth at base (Fig. 592); terminal apophysis thick, broad, rugose, concave at tip (Figs. 591, 592). Female. Total length 4.32 mm; carapace 2.20 mm long, 1.74 mm wide (1 specimen measured). Coloration as in male (Figs. 583–586). Epigynum with short scape; scape slender except at tip, tortuous, spoon-shaped distally, with many shallow grooves (Figs. 587, 588); copulatory openings long, open anteriorly; posterior plate short, broad, little wider ventrally than dorsally (Fig. 589); spermathecae elliptical, touching (ventral view, Fig. 590), dumbbell-shaped in posterior view. Range. Wisconsin to Maine, south to Arkansas and southern Georgia. Comments. Specimens of A. guttulatus are distinguished from those of other species of Araneus by the combination of slender, inclined, distally hooked

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Figs. 583–592. Araneus guttulatus. 583, 584, female, dorsal views; 585, 586, abdomen of female, dorsal views; 587–589, epigynum: 587, 588, ventral views; 589, posterior view; 590, spermathecae; 591, 592, palpus of male: 591, mesal view; 592, ventral view. con, conductor; e, embolus; ls, lateral sclerite; ma, median apophysis; pp, posterior plate; term, terminal apophysis.

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Map 72. Collection localities of Araneus guttulatus.

embolus and concave terminal apophysis, by the anteriorly open copulatory openings, and by the small paired reddish spots, associated with paired dark oblique marks, on the abdomen. Biology. Individuals of A. guttulatus are sometimes swept from their webs in swamps or bogs. Many have been collected from the nests of potter wasps.

Genus Cercidia Thorell The genus Cercidia is thought to be represented by a single species, C. prominens (Westring) (Levi 1975a). Individuals of this species are unusual in that they build their webs only a few centimetres above the ground in spaces between the stems of grasses and other low plants. They are collected by litter sifter from moss and leaf litter. Description. Total length 3.6–4.6 mm. Carapace orange-brown in preservative, orange-red in living specimens; height of front two or more times greater

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than diameter of anterior median eyes. Eyes approximately equal in size; posterior row of eyes procurved. Legs reddish yellow, with brownish rings; coxa I with hook, and femur II with corresponding groove; tibia II with 4 or 5 stout tapered macrosetae prolaterally; leg IV longer than I. Abdomen brownish to red, longer than wide, rounded posteriorly, pointed anteriorly, bearing dorsal sclerite; point with row of marginal setae (Fig. 593); sclerite weakly sclerotized, covering threefifths or more of dorsum; venter dark, bordered laterally with white (Fig. 594). Palpus of male with 2 dorsal patellar macrosetae; sclerites of genital bulb compact, strongly sclerotized; tegulum broad, rather flat; median apophysis large, oriented nearly longitudinally, with long tapered spine at each end (Figs. 598, 599); embolus slender distally, concealed by terminal apophysis; terminal apophysis thick, with tip overhanging embolus and with small pointed process near base. Epigynum with scape; scape uneven in width, with broad annulations, spoonshaped at tip, with several setae (Fig. 595); posterior plate approximately rectangular (Fig. 596); spermathecae large, oblique, wider than long (Fig. 597). Comments. Specimens of Cercidia prominens are distinguished from those of other araneid genera by the high front, long leg IV (longer than I), anteriorly pointed abdomen, weakly sclerotized abdominal sclerite, and by the row of setae at the anterior end of the abdomen. Levi (1975a) revised Cercidia, stating that C. prominens is the only species definitely known to belong to the genus, and giving the collection localities in the northeastern United States.

Cercidia prominens (Westring) Figs. 593–599; Map 73

Epeira prominens Westring, 1851:35. Cercidia prominens: Thorell 1869:49; Emerton 1913:219, fig. 11 (pl. 2); Wiehle 1931:25, figs. 10, 30–32; Kaston 1948:227, fig. 731 (pl. 34); Levi 1975a:113, figs. 47–57. Male. Total length 4.33 ± 0.20 mm; carapace 2.01 ± 0.14 mm long, 1.57 ± 0.12 mm wide (10 specimens measured). Coloration and structure as given in generic treatment. Palpus as in Figs. 598, 599. Female. Total length 4.40, 5.40 mm; carapace 1.87, 2.20 mm long, 1.60, 1.68 mm wide (2 specimens measured). Coloration and structure as given in generic treatment. Epigynum and spermathecae as in Figs. 595–597. Range. Alberta to Quebec and Massachusetts; Europe, Asia. Comments. Specimens of C. prominens are distinguished from those of other araneid genera as given in the generic treatment. Levi (1975a) regards this species as introduced in North America, basing his inference on the spotty and limited range near the eastern coast and along the Great Lakes.

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Figs. 593–599. Cercidia prominens. 593, female, dorsal view; 594, abdomen of female, ventral view; 595, 596, epigynum: 595, ventral view; 596, posterior view; 597, spermathecae; 598, 599, palpus of male: 598, mesal view; 599, ventral view. ma, median apophysis; pp, posterior plate; spt, spermathecae; term, terminal apophysis.

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Map 73. Collection localities of Cercidia prominens.

Biology. According to Wiehle (1931), the habitat of C. prominens comprises the spaces between grasses, low plants such as heather, and among mosses and plant detritus. Webs occur in open land as well as in forests, and in swampy places as well as dry, well-lighted ones. Protection by the low plants and surface detritus, and also web supports, appear to be the essential factors. The web, which is vertical or nearly so, is built during the afternoon, and dismantled the following morning between 8:00 and 10:00 hr. The web has 12–21 radii (usually 15–17), about 18 sticky spirals in the upper half, and about 27 sticky spirals in the lower half. The catching area measures 50–60 mm. The hub is often bitten out. The spider builds no retreat, but remains at the hub or in nearby plants. Levi (1975a) recorded adults in North American collections in May, July, and November.

Genus Eustala Simon Representatives of the genus Eustala are small or medium-sized orb weavers of shrubs and deciduous trees. The web is often built among dead branches. The spider is nocturnal; it spins in the evening, removes its web at daybreak, then spends the day among dead branches nearby. The web has relatively few frame threads, and the hub is filled with threads. Most webs are vertical.

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Description. Total length of males 2.5–9.5 mm, of females 3.4–11.5 mm. Carapace broad posteriorly, rather strongly narrowed toward front, often highest at level of dorsal groove (Figs. 600–604, 612–615, 622–625), brown or orangebrown, covered with setae; dorsal groove deep, longitudinal. Eyes small, with lateral eyes smaller than median eyes. Legs brown or orange-brown, sometimes ringed with dark pigment; male tibia II with macrosetae somewhat stouter than those on tibia I; coxa I of male with small hook, and femur II with groove; femora sometimes with ventral row of macrosetae (Fig. 605). Abdomen usually triangular in outline, often somewhat angular posteriorly (Figs. 602, 624); dorsum usually with pattern of black patches on paler background; venter usually with white spot (Figs. 604, 615, 625). Male palpus with single dorsal macroseta on patella; bulb with ventral sclerites oriented laterally; cymbium small; tegulum inconspicuous; median apophysis pale, conical, wormlike, extending toward base of bulb (Figs. 610, 620, 630); embolus with large sclerotized base, hooked at tip; conductor large, variously shaped according to species; terminal apophysis slender, fingerlike, resting on large transparent subterminal apophysis. Epigynum with large scape; scape pointed, extending anteriorly, usually with numerous transverse grooves and ridges (Figs. 606, 616, 626); posterior plate broad, angular or rounded, tapered dorsally (Figs. 608, 618, 628); spermathecae usually spherical (Figs. 609, 619, 629). Comments. Specimens of Eustala are distinguished from those of other araneid genera by the conical median apophysis and by the anteriorly directed epigynal scape. The wormlike pale median apophysis is also characteristic. Representatives of Eustala are known only from the New World, where an estimated 60 species occur. Levi (1977a) treated 13 species in North America north of Mexico. Three of these are represented in Canada.

Key to species of Eustala 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2(1).

Tips of embolus and conductor touching (Fig. 610) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . anastera (Walckenaer) (p. 267)

2'.

Tips of embolus and conductor distinctly separated (Figs. 620, 630) ...................................................3

3(2').

Terminal part of conductor slender (Fig. 620) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . emertoni (Banks) (p. 269)

3'.

Terminal part of conductor broader (Fig. 630) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cepina (Walckenaer) (p. 271)

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4(1').

Posterior plate of epigynum with expanded part shorter than slender part (Fig. 608). Total length greater than 5 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . anastera (Walckenaer) (p. 267)

4'.

Posterior plate of epigynum with expanded part as long as slender part (Figs. 618, 628). Total length less than 5 mm . . . . . . . . . . . . 5

5(4').

Abdomen ovoid in outline, longer than wide, without posterior tubercle (Figs. 612–615) . . . . . . . . . . . . . . . . emertoni (Banks) (p. 269)

5'.

Abdomen more angular in outline, approximately as long as wide, with posterior tubercle (Figs. 622–625) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cepina (Walckenaer) (p. 271)

Clé des espèces d’Eustala 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2(1).

Apex de l’embolus et du conducteur se touchant (fig. 610) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . anastera (Walckenaer) (p. 267)

2'.

Apex de l’embolus et du conducteur nettement sérarés (figs. 620, 630) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3(2').

Partie terminale du conducteur étroite (fig. 620) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . emertoni (Banks) (p. 269)

3'.

Partie terminale du conducteur élargie (fig. 630) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cepina (Walckenaer) (p. 271)

4(1').

Partie élargie de la plaque postérieure de l’épigyne plus courte que la partie étroite (fig. 608) . . . . . . . . . anastera (Walckenaer) (p. 267)

4'.

Partie élargie de la plaque postérieure de l’épigyne aussi longue que la partie étroite (figs. 618, 628) . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

5(4').

Abdomen plus long que large, contour de forme ovoïde, sans tubercules (figs. 612–615). Taille plus de 5 mm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . emertoni (Banks) (p. 269)

5'.

Abdomen aussi long que large, contour formant un angle, muni de tubercules sur la partie postérieure (figs. 622–625). Taille moins de 5 mm . . . . . . . . . . . . . . . . . . . . . . . . . cepina (Walckenaer) (p. 271)

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Eustala anastera (Walckenaer) Humpbacked Orbweaver Figs. 600–611; Map 74

Epeira anastera Walckenaer, 1841:33. Epeira eustala Walckenaer, 1841:37. Epeira apotroga Walckenaer, 1841:43. Epeira spatulata Walckenaer 1841:44. Epeira illustrata Walckenaer 1841:45. Epeira decolorata Walckenaer, 1841:49. Epeira triflex Walckenaer, 1841:60. Epeira trinota Walckenaer, 1841:75. Eustala anastera: Chamberlin and Ivie 1944:102, fig. 4; Kaston 1948:233, figs. 706–709 (pl. 33), 727 (pl. 34); Levi 1977a:114, plate 7, figs 205–232, 280–285, 298–302, 314, 315. Male. Total length 5.16 ± 0.82 mm; carapace 2.77 ± 0.55 mm long, 2.24 ± 0.32 mm wide (10 specimens measured). Carapace brown, darker at lateral margins (Fig. 601). Legs dark, with indistinct darker rings; femur II with 3–5 ventral macrosetae (Fig. 605). Abdomen contrastingly patterned with black, elliptical or triangular in outline, with dorsal tubercle posteriorly. Palpus with conductor con-

Map 74. Collection localities of Eustala anastera.

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Figs. 600–611. Eustala anastera. 600, female, dorsal view; 601, male, dorsal view; 602, female, lateral view; 603, male, lateral view; 604, abdomen of female, ventral view; 606–608, epigynum: 606, ventral view; 607, lateral view; 608, posterior view; 605, leg femora of male, ventral view; 609, spermathecae; 610, 611, palpus of male: 610, mesal view; 611, ventral view. con, conductor; e, embolus; ma, median apophysis; pp, posterior plate; spt, spermatheca; subterm, subterminal apophysis; term, terminal apophysis.

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vex (Figs. 610, 611); slender part of conductor shorter than embolus (mesal view, Fig. 610). Female. Total length 7.29 ± 0.94 mm; carapace 2.92 ± 0.41 mm long, 2.52 ± 0.39 mm wide (10 specimens measured). Coloration as in male but more distinct and more variable (Figs. 600, 602–604). Epigynum with long scape; scape directed anteriorly, long, slender, pointed, with numerous transverse grooves and ridges (Figs. 606, 607); posterior plate expanded ventrally, abruptly narrowed dorsally (Fig. 608); spermathecae round (Fig. 609). Range. Southern Alberta to Nova Scotia, south to California, southern Mexico, and Florida. Comments. Specimens of E. anastera are distinguished from those of other species of Eustala by the short slender part of the conductor, by the long abdomen, which bears a distinct tubercle, by the contrasting black abdominal pattern, and by the row of 3–5 macrosetae ventrally on femur II. Biology. Webs of E. anastera are commonly found among dead branches in open forests of larch, spruce, fir, pine, oak, or maple. Individuals have also been swept from goldenrod and marsh plants. They are sometimes found in the nests of mud-dauber wasps. Head (1995) analyzed the relationship between male and female size variation.

Eustala emertoni (Banks) Figs. 612–621; Map 75

Epeira emertoni Banks, 1904:111. Eustala arkansana Archer, 1951:19, fig. 54. Eustala emertoni: Kaston 1977:27; Levi 1977a:120, figs. 253–268, 291–295, 309–311, 317. Male. Total length 4.30, 4.48 mm; carapace 2.30, 2.49 mm long, 1.70, 1.95 mm wide (2 specimens measured). Carapace brownish, paler anteriorly. Legs brownish; femora with indistinct darker rings; femur II lacking ventral macrosetae; tibia II unmodified. Abdomen ovoid in outline, lacking posterior tubercle, with dark angular pattern on pale background (as in Figs. 612, 613). Palpus with large conductor; conductor convex, with slender part longer than embolus (Fig. 620); terminal apophysis slender, pointed, somewhat shorter than subterminal apophysis (Figs. 620, 621). Female. Total length 5.76 (4.73–6.72) mm; carapace 2.44 (2.08–2.82) mm long, 2.19 (1.74–2.60) mm wide (4 specimens measured). Coloration as in male. Abdomen ovoid, longer than wide, without posterior tubercle (Figs. 612–615). Epigynum with long, tapered, pointed, anteriorly directed scape (Figs. 616, 617); 269

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Figs. 612–621. Eustala emertoni. 612, female, dorsal view; 613, abdomen of female, dorsal view; 614, female, lateral view; 615, abdomen of female, ventral view; 616–618, epigynum: 616, ventral view; 617, lateral view; 618, posterior view; 619, spermathecae; 620, 621, palpus of male; 620, mesal view; 621, ventral view. con, conductor; e, embolus; ma, median apophysis; subterm, subterminal apophysis; term, terminal apophysis.

posterior sclerite expanded ventrally, abruptly narrowed dorsally, with expanded part approximately as long as slender part (Fig. 618); spermathecae round (Fig. 619).

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Map 75. Collection localities of Eustala emertoni.

Range. Wisconsin to Massachusetts, south to northeastern Mexico and Florida. Comments. Specimens of E. emertoni are distinguished from those of other species of Eustala by the ovoid abdomen, which lacks a posterior tubercle, and by the short terminal apophysis. Biology. Individuals of E. emertoni build their orb webs in fields, open forests, and marshes. Many specimens have been found in mud-dauber wasp nests.

Eustala cepina (Walckenaer) Figs. 622–631; Map 76

Epeira cepina Walckenaer, 1841:37. Epeira parvula Keyserling, 1864:131, figs. 9, 10 (pl. 6). Eustala cepina: Chamberlin and Ivie 1944:103; Levi 1977a:118, figs. 233–252, 286–290, 303–308, 316. Male. Total length 2.99, 3.30, 4.17 mm; carapace 1.69, 1.70, 1.74 mm long, 1.49, 1.50, 2.30 mm wide (3 specimens measured). Carapace orange-brown. Legs orange-brown, with indistinct darker rings; tibia II unmodified. Abdomen angu-

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Figs. 622–631. Eustala cepina. 622, female, dorsal view; 623, abdomen of female, dorsal view; 624, female, lateral view; 625, abdomen of female, ventral view; 626–628, epigynum: 626, ventral view; 627, lateral view; 628, posterior view; 629, spermathecae; 630, 631, palpus of male: 630, mesal view; 631, ventral view. con, conductor; e, embolus; ma, median apophysis.

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Map 76. Collection localities of Eustala cepina.

lar in outline, with posterior tubercle, usually with dark angular pattern on paler background (as in Figs. 622–625). Palpus with large conductor; conductor rather narrow, with slender part longer than embolus (Figs. 630, 631); terminal apophysis slender, pointed, as long as subterminal apophysis (Fig. 630). Female. Total length 5.96 ± 0.60 mm; carapace 2.29 ± 0.21 mm long, 1.98 ± 0.08 mm wide (9 specimens measured). Coloration as in male (Figs. 622–625). Abdomen as in male. Epigynum with long, pointed, anteriorly directed scape; scape with numerous transverse grooves and ridges (Figs. 626, 627); posterior plate with expanded part as long as slender part (Fig. 628); spermathecae round (Fig. 629). Range. Minnesota to Nova Scotia, south to Colorado, northeastern Mexico, and Florida. Comments. Specimens of E. cepina are distinguished from those of other species in the genus Eustala by the narrow conductor. The slender part of the posterior plate in the epigynum of female cepina is longer than that of female emertoni. Biology. Individuals of E. cepina are found in grassland, marshes, dune plants, roadside weeds, and garden crops.

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Genus Singa C.L. Koch Members of the genus Singa are small orb weavers often found in moist habitats such as the foliage of emergent water plants at the edges of ponds and swamps. Other habitats are low shrubs and herbs in moist forests. Some specimens have been collected in pitfall traps on the ground. Description. Total length of males 3.74–4.98 mm, of females 4.95–6.39 mm. Carapace shiny, with few setae, orange, longer than wide, widest at level of coxae II/III (Fig. 632). Median eyes larger than lateral eyes (Figs. 634, 643); posterior row of eyes somewhat recurved; eye region black. Legs rather slender, yellow or orange; tibia I and/or II of male sometimes thicker and provided with more prolateral macrosetae than other legs; coxa I of male with hook. Abdomen approximately twice as long as wide, overhanging spinnerets, with sides nearly parallel, and with paired broad black longitudinal bands (bands sometimes broken into large spots, or merged together) (Figs. 632, 633, 641). Palpus of male with 2 slender dorsal patellar macrosetae, or with 1 stout and 1 slender macroseta; tegulum rather flat and slender, with rounded distal prominence on ventral side of bulb; median apophysis small, with 1 or 2 small spurs (Figs. 639, 647); embolus slender and pointed or thicker and obliquely truncate, sometimes with lamella (Figs. 639, 640, 647, 648); terminal apophysis thick, curved, pointed (Figs. 640, 648). Epigynum with scape; scape broad, spoonlike, attached at anterior margin of epigynal plate, sometimes with several setae (Figs. 635, 644); posterior plate large, approximately as wide as long (Figs. 636, 645); spermathecae large, oblique, dumbbell-shaped, nearly touching (Figs. 637, 638, 646). Comments. Members of the genus Singa are distinguished from those of other araneid genera by the black eye region, by the abdominal shape and color, by the rounded distal prominence on the palpal tegulum, and by the large dumbbell-shaped spermathecae. Known members of the genus are restricted to Europe, Asia, and temperate North America. Levi (1972) revised the two North American species, both of which are represented in Canada.

Key to species of Singa 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2(1).

Median apophysis with 1 spur (Figs. 639, 640) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . keyserlingi McCook (p. 275)

2'.

Median apophysis with 2 spurs (Figs. 647, 648) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . eugeni Levi (p. 277)

3(1').

Epigynal plate nearly straight and somewhat oblique at sides (Figs. 635, 636) . . . . . . . . . . . . . . . . keyserlingi McCook (p. 275)

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Epigynal plate rounded at sides (Figs. 644, 645) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . eugeni Levi (p. 277)

Clé des espèces de Singa 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2(1).

Apophyse médiane munie d’un éperon (figs. 639, 640) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . keyserlingi McCook (p. 275)

2'.

Apophyse médiane munie de 2 éperons (figs. 647, 648) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . eugeni Levi (p. 277)

3(1').

Bordures de la plaque de l’épigyne obliques et presque rectilignes (figs. 635, 636) . . . . . . . . . . . . . . . . keyserlingi McCook (p. 275)

3'.

Bordures de la plaque de l’épigyne arrondies (figs. 644, 645) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . eugeni Levi (p. 277)

Singa keyserlingi McCook Figs. 632–640; Map 77

Singa keyserlingi McCook, 1894:230, fig. 2 (pl. 19); Levi 1972:232, figs. 9–24; 1975b:272. Singa campestris Emerton, 1915b:153, fig. 3 (pl. 3). Male. Total length 4.04 (3.74–4.40) mm; carapace 2.09 (1.95–2.20) mm long, 1.59 (1.54–1.60) mm wide (5 specimens measured). Carapace orange, with eye area black. Legs orange, with darker pigment toward tips of segments; tibiae I and II with stout macrosetae prolaterally. Abdomen black dorsally; venter dark. Palpus with 2 slender patellar macrosetae; median apophysis with 1 spur (Figs. 639, 640); embolus long, slender, somewhat curved (Fig. 639). Female. Total length 5.52 ± 0.49 mm; carapace 2.00 ± 0.16 mm long, 1.58 ± 0.12 mm wide (10 specimens measured). Coloration as in male, but black area on carapace more extensive, and that of abdominal dorsum divided into 2 broad longitudinal bands (Figs. 632–634). Epigynum with broad, rounded spoonlike scape (Fig. 635); scape with several setae; epigynal plate with sides nearly straight, oblique (Figs. 635, 636); spermathecae large, dumbbell-shaped, oblique (Figs. 637, 638). Range. Interior British Columbia to Quebec, south to Missouri and northern Alabama.

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Figs. 632–640. Singa keyserlingi. 632, female, dorsal view; 633, abdomen of female, lateral view; 634, eyes and chelicerae of female, anterior view; 635, 636, epigynum: 635, ventral view; 636, posterior view; 637, 638, spermathecae: 637, dorsal view; 638, ventral view; 639, 640, palpus of male: 639, mesal view; 640, ventral view. e, embolus; ma, median apophysis; spt, spermatheca; teg, tegulum; term, terminal apophysis.

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Map 77. Collection localities of Singa keyserlingi.

Comments. Specimens of S. keyserlingi are distinguished from those of S. eugeni by the single spur on the median apophysis, and by the oblique, nearly straight lateral margins on the epigynal plate. Biology. Specimens of S. keyserlingi have been collected from low plants in open moist forests, and from tall grasses at the margins of lakes. Adults are present from May to September.

Singa eugeni Levi Figs. 641–648; Map 78

Singa eugeni Levi, 1972:236, figs. 25–34; 1975b:273. Male. Total length 4.43 (3.90–4.98) mm; carapace 2.17 (1.91–2.57) mm long, 1.49 (1.33–1.76) mm wide (6 specimens measured). Carapace orange, with eye region black. Legs yellow; tibia II thicker than other leg tibiae, somewhat curved, with several stout macrosetae prolaterally. Abdomen with 2 broad longitudinal black bands; bands sometimes reduced to 2 pairs of black spots; venter yellowish, darker mesally. Palpus with 1 stout and 1 slender patellar macrosetae; median apophysis with 2 pointed spurs (1 at each end) (Figs. 647, 648); embolus rather stout, obliquely truncate at tip (Fig. 647). 277

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Figs. 641–648. Singa eugeni. 641, female, dorsal view; 642, abdomen of female, lateral view; 643, eyes and chelicerae of female, anterior view; 644, 645, epigynum: 644, ventral view; 645, posterior view; 646, spermathecae; 647, 648, palpus of male: 647, mesal view; 648, ventral view. e, embolus; ma, median apophysis; teg, tegulum.

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Map 78. Collection localities of Singa eugeni.

Female. Total length 6.39, 5.06, 5.60 mm; carapace 2.08, 2.16, 2.20 mm long, 1.38, 1.49, 1.60 mm wide (3 specimens measured). Coloration as in male (Figs. 641, 642). Epigynum with large, elliptical scape; scape with several setae (Fig. 644); epigynal plate large, rounded at lateral margins (Figs. 644, 645); spermathecae large, dumbbell-shaped, oblique (Fig. 646). Range. Wisconsin to Pennsylvania, south to Georgia. Comments. Specimens of S. eugeni are distinguished from those of S. keyserlingi by the 2 spurs on the median apophysis and by the rounded lateral margins of the epigynal plate. Biology. Specimens of S. eugeni were collected from flood plain forests, along rivers, and in marshes (Levi 1972).

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Genus Hypsosinga Ausserer Members of the genus Hypsosinga are small orb weavers found in herbs and low shrubs in meadows and roadsides. One species, H. groenlandica Simon, is noteworthy for its range, which includes Greenland and arctic Canada. Specimens are collected with sweep nets. The web, where known, is a complete orb, and it may have a retreat. Description. Total length 2.2–5.1 mm. Carapace shiny, orange, with eye area black; front 1.5–3.0 times as high as diameter of anterior median eyes (Figs. 651, 661, 669, 677, 690). Posterior row of eyes straight or somewhat recurved; posterior median eyes larger than other eyes; median ocular quadrangle rectangular, or wider posteriorly. Legs orange, rarely with dark stripes or bands; coxa I of males lacking hook; tibia I of males swollen. Abdomen rotund, broadly elliptical in outline, with few setae; dorsal pattern consisting of paired dark longitudinal bands or large paired spots (Figs. 649, 650, 659, 668, 675, 676, 688, 689); dorsum rarely totally black. Palpus of male with 2 dorsal patellar macrosetae; tegulum occupying basal half or more of genital bulb (ventral view, Figs. 658, 665, 684, 685), with strong spur (Figs. 657, 673, 684); median apophysis small, with 1 slender curved spur; embolus long and hairlike or shorter and stouter (Figs. 657, 667, 673, 686, 687, 696), in unmated males with large partly transparent scale; terminal apophysis small or large, arched over tip of genital bulb (Figs. 657, 666, 673, 684). Epigynum without scape; median septum usually concave at sides (Figs. 653, 662, 678, 681, 691), sometimes rectangular (Fig. 670); posterior plate large, usually angular (Figs. 654, 663, 671, 679, 682); spermathecae round, elliptical, or dumbbell-shaped, nearly touching at midline (Figs. 655, 656, 664, 672, 680, 683, 693). Comments. Specimens of Hypsosinga are distinguished from those of other araneid genera by the high front, by the spur on the tegulum, and by the large, partly transparent scale on the embolus, which may be broken off during mating and lodged in the copulatory openings of the female (Fig. 652). Levi (1972, 1975b) revised the five species represented in America north of Mexico. All five are represented in Canada.

Key to species of Hypsosinga 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2(1).

Embolus threadlike (Figs. 657, 658) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pygmaea (Sundevall) (p. 282)

2'.

Embolus not threadlike, instead broad at base and tapered abruptly to point (Figs. 667, 674, 686, 687, 694, 696) . . . . . . . . . . . . . . . . . . 3

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3(2').

Tegulum with serrated crest (Figs. 665, 674) . . . . . . . . . . . . . . . . 4

3'.

Tegulum without serrated crest, instead with spur . . . . . . . . . . . . 5

4(3).

Tegular crest with single large projection (at mesal end, Fig. 665) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . groenlandica Simon (p. 285)

4'.

Tegular crest with 2 large projections (1 at each end, Figs. 673, 674) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . alberta Levi (p. 287)

5(3').

Embolus slender distally (Figs. 686, 687). . . rubens (Hentz) (p. 289)

5'.

Embolus broad, abruptly tapered (Figs. 694, 696) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . funebris (Keyserling) (p. 292)

6(1').

Median septum of epigynum raised (Figs. 653, 662, 678, 681, 691, 692) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

6'.

Median septum depressed (Fig. 670) . . . . . . . alberta Levi (p. 287)

7(6).

Median septum approximately rectangular (Figs. 652, 653) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pygmaea (Sundevall) (p. 282)

7'.

Median septum triangular (Figs. 678, 681) or laterally concave (Figs. 662, 691, 692) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

8(7').

Median septum approximately triangular (Figs. 678, 681) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . rubens (Hentz) (p. 289)

8'.

Median septum laterally concave (Figs. 662, 691, 692) . . . . . . . . 9

9(8').

Median septum as long as wide (Figs. 691, 692) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . funebris (Keyserling) (p. 292)

9'.

Median septum much longer than wide (Fig. 662) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . groenlandica Simon (p. 285)

Clé des espèces d’Hypsosinga 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2(1).

Embolus filiforme (figs. 657, 658). . . pygmaea (Sundevall) (p. 282)

2'.

Embolus non filiforme, plutôt élargi à la base, se terminant brusquement en une pointe (figs. 667, 674, 686, 687, 694, 696) . . . . . . . . 3

3(2').

Tégulum orné d’une carène dentelée (figs. 665, 674) . . . . . . . . . . 4

3'.

Tegulum sans carène dentelée, portant plutôt une seule pointe . . . 5

4(3).

Carène du tégulum munie d’une seule projection à l’extrémité (fig. 665) . . . . . . . . . . . . . . . . . . . . . groenlandica Simon (p. 285) 281

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4'.

Carène du tégulum munie de 2 projections, une à chaque extrémité (figs. 673, 674) . . . . . . . . . . . . . . . . . . . . . . . alberta Levi (p. 287)

5(3').

Embolus mince et étroit (figs. 686, 687) . . rubens (Hentz) (p. 289)

5'.

Embolus élargi, rétrécissant brusquement (figs. 694, 696) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . funebris (Keyserling) (p. 292)

6(1').

Septum médian de l’épigyne surélevé (figs. 653, 662, 678, 681, 691, 692) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

6'.

Septum médian formant une dépression (fig. 670) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . alberta Levi (p. 287)

7(6).

Septum médian presque rectangulaire (figs. 652, 653) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pygmaea (Sundevall) (p. 282)

7'.

Septum médian triangulaire (figs. 678, 681), ou aux rebords concaves (figs. 662, 691, 692) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

8(7').

Septum médian presque triangulaire (figs. 678, 681) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . rubens (Hentz) (p. 289)

8'.

Septum médian aux rebords concaves (figs. 662, 691, 692) . . . . . 9

9(8').

Septum médian aussi long que large (figs. 691, 692) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . funebris (Keyserling) (p. 292)

9'.

Septum médian beaucoup plus long que large (fig. 662) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . groenlandica Simon (p. 285)

Hypsosinga pygmaea (Sundevall) Figs. 649–658; Map 79

Theridion pygmaea Sundevall, 1832:121. Singa variabilis Emerton, 1885:322, figs. 16 (pl. 34), 19–21 (pl. 37); Kaston 1948:241, figs. 760–765 (pl. 36). Microneta distincta Banks, 1892:48, fig. 53 (pl. 2). Linyphia bicolor Banks, 1906:97. Name preoccupied in genus Linyphia. Singa cubana Banks, 1909:157, fig. 8 (pl. 45). Linyphia banksi Petrunkevitch, 1911:246. New name for Linyphia bicolor Banks, preoccupied. Araneus varians Petrunkevitch, 1911:323. Name preoccupied in genus Araneus. Singa pygmaea: Wiehle 1931:47, figs. 64, 65. Singa melania Chamberlin and Ivie, 1947:64.

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Figs. 649–658. Hypsosinga pygmaea. 649, female, dorsal view; 650, abdomen of female, lateral view; 651, eyes and chelicerae of female, anterior view; 652–654, epigynum: 652, ventral view showing male sclerites; 653, ventral view without male sclerites; 654, posterior view; 655, 656, spermathecae: 655, dorsal view; 656, posterior view; 657, 658, palpus of male: 657, ventral view; 658, retrolateral view. e, embolus; pp, posterior plate; teg, tegulum; term, terminal apophysis.

283

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Map 79. Collection localities of Hypsosinga pygmaea.

Araneus itemvarians Bonnet, 1955:523. New name for Araneus varians Petrunkevitch. Hypsosinga variabilis: Levi 1972:242, figs. 44–57. Hypsosinga pygmaea: Levi 1975b:273, fig. 21; Roberts 1985:218, fig. 98c. Male. Total length 2.37 ± 0.42 mm; carapace 1.27 ± 0.11 mm long, 1.10 ± 0.05 mm wide (10 specimens measured). Carapace pale orange, with eye area black. Legs orange, without dark bands. Abdominal dorsum variable, often black, sometimes with light mesal markings and paired black spots, rarely with paired broad black longitudinal bands. Palpus with 2 dorsal patellar macrosetae; tegulum with short pointed spur (Fig. 657); median apophysis small, with single long curved spur (Fig. 657); embolus long, hairlike, lying for much of its length within curve of terminal apophysis (Figs. 657, 658); terminal apophysis broad, rather flat, curving over tip of genital bulb.

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Female. Total length 3.54 ± 0.40 mm; carapace 1.42 ± 0.11 mm long, 1.24 ± 0.12 mm wide (10 specimens measured). Coloration as in male, but pale areas on abdomen often more extensive (Figs. 649–651). Epigynum with median septum approximately rectangular (Fig. 653); one or both copulatory openings often blocked by embolar scale of male (Fig. 652); posterior plate longer than wide (Fig. 654); spermathecae dumbbell-shaped or ovoid, oblique, nearly touching at midline (Figs. 655, 656). Range. Alaska to Newfoundland, south to Colorado, southern Illinois, Florida, and Cuba; Europe, Asia. Comments. Specimens of H. pygmaea are distinguished from those of other species of Hypsosinga by the long hairlike embolus and by the raised rectangular median septum. Biology. Specimens of H. pygmaea have been collected by sweep net in wet meadows and roadside weeds. According to Kaston (1948) and Wiehle (1931), half-grown individuals overwinter, and maturity is attained the following May or June. Wiehle (1931) describes the web as situated 25–30 cm above the ground, and having about 20 radials and a distinct free zone. The spider stays at the hub during the day, as no retreat is made.

Hypsosinga groenlandica Simon Figs. 659–667; Map 80

Hypsosinga groenlandica Simon, 1889:290; Levi 1972:254, figs. 89–98; 1975b:274. Singa (Hypsosinga) groenlandica: Holm 1960:512, fig. 2; 1967:69, figs. 86, 87. Male. Total length 3.39 ± 0.34 mm; carapace 1.70 ± 0.07 mm long, 1.43 ± 0.06 mm wide (10 specimens measured). Carapace orange, smooth. Eyes ringed with black. Legs orange; tibia I enlarged, with strong macrosetae. Abdomen variable, with weak dorsal sclerite, and usually with dark markings on pale background (Fig. 659); venter dark, bordered with white (Fig. 660). Palpus with 2 patellar macrosetae; tegulum with serrated crest (Fig. 665); crest with single large tooth at mesal end; median apophysis small, with single long curved spur (Figs. 665, 666); embolus broad at base, tapered abruptly to point (Fig. 667); terminal apophysis broad, thick, arched over tip of genital bulb. Female. Total length 3.69 (3.15–4.23) mm; carapace 1.51 (1.35–1.74) mm long, 1.34 (1.12–1.62) mm wide (6 specimens measured). Coloration as in male (Figs. 659–661). Abdomen lacking dorsal sclerite. Epigynum broader than long (Fig. 662); median septum strongly concave at sides, narrow at posterior end

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Figs. 659–667. Hypsosinga groenlandica. 659, female, dorsal view; 660, abdomen of female, ventral view; 661, eyes and chelicerae of female, anterior view; 662, 663, epigynum: 662, ventral view; 663, posterior view; 664, spermathecae; 665–667, palpus of male: 665, ventral view; 666, mesal view; 667, embolus. ma, median apophysis; teg, tegulum.

(Figs. 662, 663), often blocked by embolar scales of male; spermathecae large, round, well separated (Fig. 664). Range. Yukon Territory and western Northwest Territories to Greenland, south to southern British Columbia and Quebec. Comments. Specimens of H. groenlandica are distinguished from those of other species in the genus by the serrated margin on the tegulum and by the posteriorly narrow median septum.

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Map 80. Collection localities of Hypsosinga groenlandica.

Biology. Specimens of H. groenlandica have been collected from low plants on arctic tundra and from alpine tundra in the Cordillera of western North America, and also on Mt. Albert, Quebec.

Hypsosinga alberta Levi Figs. 668–674; Map 81

Hypsosinga alberta Levi, 1972:254, figs. 99–106; 1975b:274. Male. Total length 3.30, 5.00 mm; carapace 1.66, 1.70 mm long, 1.36, 1.60 mm wide (2 specimens measured). Carapace orange to yellowish. Eyes ringed with black. Legs orange or yellowish; tibia I curved, somewhat swollen, with stout prolateral macrosetae. Abdomen grayish or brownish dorsally, with weak dorsal sclerite. Palpus with 2 patellar macrosetae; tegulum with serrated crest; crest with strong tooth at each end (Figs. 673, 674); median apophysis small, with long slender spur (Fig. 673); embolus long, curved, arched over distal end of genital bulb; terminal apophysis weakly sclerotized, arched over distal end of genital bulb in association with embolus (Figs. 673, 674). Female. Total length 4.25 (3.57–5.00) mm; carapace 1.70 (1.49–1.88) mm long, 1.39 (1.33–1.45) mm wide (7 specimens measured). Coloration as in male,

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Figs. 668–674. Hypsosinga alberta. 668, female, dorsal view; 669, eyes and chelicerae of female, anterior view; 670, 671, epigynum: 670, ventral view; 671, posterior view; 672, spermathecae; 673, 674, palpus of male: 673, mesal view; 674, ventral view. ma, median apophysis; teg, tegulum; term, terminal apophysis.

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Map 81. Collection localities of Hypsosinga alberta.

but abdominal dorsum paler and lacking sclerite (Figs. 668, 669). Epigynum broader than long; median septum depressed in anterior half, somewhat narrowed at posterior end (Fig. 670); copulatory openings often blocked by embolar scales of male; posterior plate approximately rectangular (Fig. 671); spermathecae small, dumbbell-shaped, nearly touching (Fig. 672). Range. Northern British Columbia, south to central Saskatchewan; northeast Asia. Comments. Specimens of H. alberta are distinguished from those of other species in the genus by the arched embolus, by the 2 spurs on the tegular crest, and by the anteriorly depressed median septum. Biology. Specimens of H. alberta have been collected by sweep net from dwarf willow and other shrubs. One specimen was taken in a pitfall trap in wet tundra. Adults are present in July and August.

Hypsosinga rubens (Hentz) Figs. 675–687; Map 82

Epeira rubens Hentz, 1847:477, fig. 18 (pl. 31). Singa maculata Emerton, 1885:323, fig. 18 (pl. 37). Name preoccupied in genus Singa. 289

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Singa nigripes Keyserling, 1884:655, fig. 7 (pl. 21). Singa modesta Banks, 1896a:70. Singa truncata Banks, 1901:188. New name for Singa maculata Emerton, preoccupied; Kaston 1948:241, figs. 746 (pl. 35), 766 (pl. 36). Singa hentzi Banks, 1907:740, fig. 20. Araneus tusus Petrunkevitch, 1911:321. New name for Singa truncata Banks. Hypsosinga rubens: Levi 1972:248, figs. 72–88. Male. Total length 2.62 ± 0.18 mm; carapace 1.30 ± 0.11 mm long, 1.11 ± 0.11 mm wide (10 specimens measured). Carapace orange, with eye area black. Legs orange, with distal segments somewhat darkened; tibia I somewhat thickened at base. Abdomen usually orange, sometimes with paired indistinct dark spots posteriorly, or entirely black. Palpus with 2 patellar macrosetae; tegulum with rather long spur (Figs. 684–687); median apophysis small, with 1 slender

Map 82. Collection localities of Hypsosinga rubens.

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Figs. 675–687. Hypsosinga rubens. 675, female, dorsal view; 676, abdomen of female, lateral view; 677, eyes and chelicerae of female, anterior view; 678, 679, 681, 682, epigynum: 678, 681, ventral views; 679, 682, posterior views; 680, 683, spermathecae: 680, ventral view; 683, posterior view; 684–687, palpus of male: 684, mesal view; 685, ventral view; 686, 687, embolus: 686, mesal view; 687, mesoventral view. e, embolus; ma, median apophysis; teg, tegulum; term, terminal apophysis.

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curved spur (Figs. 684, 685); embolus short, curved, slender (Figs. 686, 687); terminal apophysis broad, thick, curved over tip of genital bulb. Female. Total length 3.31 ± 0.48 mm; carapace 1.28 ± 0.18 mm long, 1.11 ± 0.13 mm wide (10 specimens measured). Coloration as in male (Figs. 675–677). Epigynum with triangular median septum (Figs. 678, 681); copulatory openings sometimes blocked by embolar scales of male; posterior plate variable (Figs. 679, 682); spermathecae large, round, nearly touching (Figs. 680, 683). Range. Western Northwest Territories to Newfoundland, south to eastern Texas and Florida. Comments. Specimens of H. rubens are distinguished from those of other species in the genus by the distally slender embolus and by the triangular median septum. Biology. Specimens of H. rubens have been collected by sweep nets from shrubs or herbs in forests, and also by searches in leaf litter or under loose bark. Adults have been taken from May to July.

Hypsosinga funebris (Keyserling) Figs. 688–696; Map 83

Cercidia funebris Keyserling, 1892:37, fig. 32 (pl. 2). Araneus singaeformis Scheffer, 1904b:259, figs. 4–6 (pl. 77). Singa schefferi Banks, 1910:40. Singa orotes Archer, 1951:41, figs. 36, 37, 61. Hypsosinga singaeformis: Levi 1972:246, figs. 58–71. Hypsosinga funebris: Levi 1975b:273. Male. Total length 2.70, 2.99 mm; carapace 1.30, 1.38 mm long, 1.30, 1.33 mm wide (2 specimens measured). Carapace pale orange. Eyes ringed with black. Legs orange or yellowish; tibia I expanded basally. Abdomen grayish or brownish, with few paired black spots, and with weak sclerite covering much of dorsum. Palpus with 2 patellar macrosetae; tegulum with strong pointed spur on distal margin (Fig. 695); median apophysis small, with single curved spur (Fig. 695); embolus broad at base, abruptly tapered to sharp tip (Fig. 696); terminal apophysis broad, thick, bent at right angle near its middle (Figs. 694–696). Female. Total length 3.41 (2.91–3.98) mm; carapace 1.48 (1.40–1.59) mm long, 1.29 (1.10–1.49) mm wide (7 specimens measured). Coloration as in male (Figs. 688–690). Abdomen lacking dorsal sclerite. Epigynum broader than long (Fig. 691); median septum strongly concave at sides, broad at posterior end (Figs. 691–693), sometimes with embolar sclerite of male stuck in copulatory

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Figs. 688–696. Hypsosinga funebris. 688, female, dorsal view; 689, abdomen of female, lateral view; 690, eyes and chelicerae of female, anterior view; 691, 692, epigynum: 691, ventral view; 692, posterior view; 693, spermathecae; 694–696, palpus of male: 694, mesal view; 695, ventral view; 696, embolus. ma, median apophysis; teg, tegulum; term, terminal apophysis.

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Map 83. Collection localities of Hypsosinga funebris.

openings; posterior plate broad at middle, tapered anteriorly and posteriorly; spermathecae large, elliptical, nearly touching at midline (Fig. 693). Range. Central Alberta to southern Maine, south to California, Texas, and Florida. Comments. Specimens of H. funebris are distinguished from those of other species in the genus by the bent terminal apophysis and by the posteriorly wide median septum. Biology. Specimens of H. funebris have been collected from grass, weeds, and other herbs in fields and meadows, and also from litter. Adults are present from May to August.

Genus Zygiella F.O. Pickard-Cambridge Members of the genus Zygiella build vertical orb webs which feature a vacant sector in the upper half (Fig. 697). A signal line extends from the hub through the vacant sector to the retreat. The webs are usually found on shrubs, hedges, tree trunks, cliffs, buildings, bridges, fences, or boulders. The spiders are nocturnal.

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Fig. 697. Web of Zygiella sp.

Description. Total length 4.8–10.0 mm. Carapace smooth, glabrous or with few short setae, rather low, strongly narrowed in anterior third, yellowish, orange, or dusky, sometimes with few black lines anteriorly (Figs. 698, 704). Eyes small; anterior median eyes largest; lateral eyes on each side touching; posterior row of eyes straight or somewhat recurved. Legs slender, yellow or orange, sometimes with indistinct brownish rings; leg I longest, with numerous pale weak macrosetae, in males lacking sexual modifications. Abdomen plump, firm, smooth, elliptical in outline, somewhat flattened dorsally, with pattern of black patches in two longitudinal rows on background of yellow, silver, or white (Figs. 698, 704); venter with broad black longitudinal band extending from genital groove to spinnerets; band flanked by white bands (Fig 705). Palpus of male (Figs. 702, 703, 709, 710, 717, 718, 723–725) with sclerites of genital bulb facing ventrally; tegu-

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lum elongate; median apophysis situated near base of bulb, sometimes toothed or with ridges and grooves (Figs. 702, 718, 725); embolus arising distally, directed basally; terminal apophysis present or absent; paracymbium small, flattened; tibia usually much shorter than cymbium, sometimes much longer than cymbium and covered with long erect setae. Epigynum (Figs. 699, 706, 711, 712, 719) usually lacking scape, usually with depressed angular plate posteriorly; anterior margin usually raised, thickened, dark; spermathecae small (Figs. 701, 708, 715, 722). Comments. The smooth elliptical abdomen, with patterns of paired dark patches, superficially resembles that of representatives of Enoplognatha spp. (Theridiidae), but the members of Zygiella are true orb weavers. Their relationship to the genera of Araneidae is indicated by the structure of the external genitalia, though earlier authors tended to favor placement among the “metines” (Tetragnathidae). Members of the genus Zygiella are distinguished from those of other orb-weaver genera by the plump ornamented elliptical abdomen, by the flattened paracymbium, and by the vacant, or open, sector of the web. Levi (1974a) estimated a world fauna of about 15 species, of which four are represented in North America. All four are represented in Canada.

Key to species of Zygiella 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2(1).

Palpal tibia much longer than cymbium (Fig. 703) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . atrica C.L. Koch (p. 298)

2'.

Palpal tibia much shorter than cymbium . . . . . . . . . . . . . . . . . . . 3

3(2).

Palpal tegulum with toothlike process (Figs. 717, 723) . . . . . . . . 4

3'.

Palpal tegulum lacking process (Figs. 709, 710) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x-notata (Clerck) (p. 300)

4(3').

Median apophysis with 12 or more minute teeth on ridge (Figs. 717, 718). Carapace width usually greater than 2.0 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . dispar (Kulczy½ski) (p. 303)

4'.

Median apophysis with 7–10 larger teeth on ridge (Figs. 724, 725). Carapace width usually less than 2.0 mm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . nearctica Gertsch (p. 306)

5(1')

Epigynum with depressed posterior plate, visible in ventral view (Figs. 699, 711, 712, 719) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5'.

Epigynum without depressed posterior plate (Fig. 706) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x-notata C.L. Koch (p. 300)

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6(5).

Posterior plate of epigynum occupying approximately one-half epigynal width (Fig. 700) . . . . . . . . . . . . . . atrica C.L. Koch (p. 298)

6'.

Posterior plate of epigynum occupying approximately one-third epigynal width (Figs. 713, 716, 720, 721) . . . . . . . . . . . . . . . . . . . . . 7

7(6')

Epigynum with distinct anterior rim (Figs. 711, 714, 716); lateral areas of epigynum flat. Carapace width usually greater than 2.0 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . dispar (Kulczy½ski) (p. 303)

7'.

Epigynum lacking distinct anterior rim (Figs. 719, 720, 721); lateral areas of epigynum prominent. Carapace width usually less than 2.0 mm . . . . . . . . . . . . . . . . . . . . . . . . . nearctica Gertsch (p. 306)

Clé des espèces de Zygiella 1.

Mâle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2(1).

Tibia du palpe beaucoup plus long que le cymbium (fig. 703) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . atrica C.L. Koch (p. 298)

2'.

Tibia du palpe beaucoup plus court que le cymbium . . . . . . . . . . 3

3(2').

Tégulum du palpe orné d’une protubérance en forme de dent (figs. 717, 723) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3'.

Tégulum du palpe sans protubérance (figs. 709, 710) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x-notata (Clerck) (p. 300)

4(3').

Carène de l’apophyse médiane munie d’une douzaine de petites dents (figs. 717, 718). Largeur du céphalothorax habituellement de plus de 2.0 mm . . . . . . . . . . . . . . . . . . . . . . . . dispar (Kulczy½ski) (p. 303)

4'.

Carène de l’apophyse médiane munie de 7 à 10 dents, légèrement plus robustes (figs. 724, 725). Largeur du céphalothorax habituellement de moins de 2.0 mm . . . . . . . . . . . nearctica Gertsch (p. 306)

5(1').

Plaque postérieure de l’épigyne creuse, visible en vue ventrale (figs. 699, 711, 712, 719) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5'.

Épigyne sans plaque postérieure creuse (fig. 706) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x-notata C.L. Koch (p. 300)

6(5).

Plaque postérieure de l’épigyne occupant près la moitié de la largeur de l’épigyne (fig. 700) . . . . . . . . . . . . . . . atrica C.L. Koch (p. 298)

6'.

Plaque postérieure de l’épigyne occupant près du tiers de la largeur de l’épigyne (figs. 713, 716, 720, 721) . . . . . . . . . . . . . . . . . . . . 7

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7(6').

Épigyne munie d’une bordure antérieure surélevée, régions latérales de l’épigyne aplatie et sans élévations (figs. 711, 714, 716). Largeur du céphalothorax habituellement de plus de 2.0 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . dispar (Kulczy½ski) (p. 303)

7'.

Épigyne sans bordure antérieure surélevée, régions latérales saillantes (figs. 719, 720, 721). Largeur du céphalothorax habituellement de moins de 2.0 mm . . . . . . . . . . . . . . . nearctica Gertsch (p. 306)

Zygiella atrica (C.L. Koch) Figs. 698–703; Map 84

Eucharia atrica C.L. Koch, 1843c:103, figs. 1030, 1031. Zilla atrica: Wiehle 1931:33, figs. 38–40. Zygiella atrica: Gertsch 1964:16, figs. 18–20; Levi 1974a:272, plate 1, figs. 1–8; Roberts 1985:220, fig. 99d. Male. Total length 4.89 ± 0.61 mm; carapace 2.60 ± 0.36 mm long, 1.96 ± 0.27 mm wide (10 specimens measured). Carapace yellow to orange, darker anteriorly, often with dark median longitudinal band anterior to dorsal groove. Anterior row of eyes somewhat recurved; posterior row of eyes nearly straight. Legs yellowish or orange, usually with distinct dark rings. Abdomen silvery or white, with pattern of black patches arranged in two longitudinal rows (Fig. 698).

Map 84. Collection localities of Zygiella atrica.

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Figs. 698–703. Zygiella atrica. 698, female, dorsal view; 699, 700, epigynum: 699, ventral view; 700, posterior view; 701, spermathecae; 702, 703, palpus of male: 702, ventral view; 703, retrolateral view. e, embolus; ma, median apophysis; pc, paracymbium; term, terminal apophysis.

Palpus with tibia approximately twice as long as cymbium, with many long erect setae (Fig. 703); tegulum elongate, lacking basal process; median apophysis basal, with 2 short pointed teeth (Fig. 702); embolus broad at base, smoothly tapered distally (Fig. 702); terminal apophysis lacking; paracymbium flat, terminating in slender point (Fig. 703). 299

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Female. Total length 6.12 ± 1.14 mm; carapace 2.46 ± 0.33 mm long, 1.89 ± 0.21 mm wide (10 specimens measured). Coloration essentially as in male, but carapace often with dark triangle at midline anterior to dorsal groove, and with three dark lines radiating from triangle (Fig. 698). Epigynum (Figs. 699, 700) with broad angular depressed plate posteriorly, and with wide raised dark anterior margin; posterior plate doubly arched (posterior view, Fig. 700); spermathecae rather small, round, separated by their radius (Fig. 701). Range. Eastern seaboard from Newfoundland to Long Island, and shores of the Great Lakes; Vancouver area and southern coast of Vancouver Island; Europe, Asia. The spider is regarded as introduced in North America, the earliest specimens having been recorded about 1885 (Gertsch 1964). The single known Lake Ontario record may be the result of a chance introduction rather than of an established population. Comments. Adults of Z. atrica are distinguished from those of other species in the genus by the greatly elongated setaceous palpal tibia of males, by the lack of processes on the palpal tegulum, and by the broad epigynal plate. Biology. Levi (1974a) observed large numbers of individuals among the boulders of a sea wall on the Nahant peninsula, Massachusetts. Later, Levi (unpublished) did not find any specimens at that locality. The senior author (C.D.D.) observed a similar population on boulders forming a breakwater at Pleasant Bay, Cape Breton Island, in 1984. Wiehle (1931) recorded individuals on heath plants and thickets along the sea coast of northern Germany, and also on fence rails, window frames, and doorways of stables and sheds. The web has 38–54 radii, most of which are in the lower half of the web, and 23–40 sticky spirals. A catching area of 120 mm was reported by Wiehle (1931). The hub is finely meshed, and the attachment zone sometimes impinges on the free zone so that the latter may become indistinguishable. Mature individuals appear in late August, and mating occurs at that time. Eggs, which are the overwintering stage, are laid in white sacs and secreted in crevices near the web.

Zygiella x-notata (Clerck) Figs. 704–710; Map 85

Araneus x-notata Clerck, 1758:46, fig. 5 (pl. 2). Zilla boesenbergii Keyserling, 1878:575, figs. 4, 5 (pl. 14). Zilla californica Banks, 1896b:90. Larinia maulliana Mello-Leitão, 1951:331, figs. 5, 6. Zygiella x-notata: Simon 1929:663; Gertsch 1964:12, figs. 2, 15–17; Levi 1974a:276, figs. 21–31, 57, 58; Roberts 1985:220, fig. 99c. Pseudometa biologica Chamberlin, 1925:217.

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Figs. 704–710. Zygiella x-notata. 704, female, dorsal view; 705, abdomen of female, ventral view; 706, 707, epigynum: 706, ventral view; 707, posterior view; 708, spermathecae; 709, 710, palpus of male: 709, ventral view; 710, retrolateral view. e, embolus; ma, median apophysis; pc, paracymbium.

Male. Total length 5.48 (5.23–5.64) mm; carapace 2.89 (2.66–3.35) mm long, 2.22 (2.15–2.28) mm wide (4 specimens measured). Carapace dull yellow to orange, darker anteriorly. Legs yellow to orange. Abdomen silvery, with pattern of black patches arranged in two longitudinal rows. Palpal tibia approxi-

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Map 85. Collection localities of Zygiella x-notata.

mately two-thirds as long as cymbium; tegulum lacking prominence (Fig. 710); median apophysis with 2 blunt teeth (Fig. 710); embolus broad at base, slender and curved distally (Fig. 709); terminal apophysis lacking; paracymbium flattened, with small point distally (Fig. 710). Female. Total length 6.26 (5.48–7.52) mm; carapace 2.60 (2.08–2.82) mm long, 2.04 (1.76–2.41) mm wide (7 specimens measured). Coloration as in male, but carapace often with dark triangular mark and slender lines anterior to dorsal groove (Figs. 704, 705). Epigynum (Figs. 706, 707) lacking depressed posterior plate, with anterior margin broad, much thickened and darkened; spermathecae small, round, separated by their radius (Fig. 708). Range. Atlantic coast from Maine to Virginia, and Pacific coast from southern British Columbia to southern California; temperate South America, Europe, Asia. Comments. Specimens of Z. x-notata are distinguished from those of other species of Zygiella by the absence of a toothlike process at the base of the tegulum, and by the lack of a depressed posterior plate and possession of a broad thick anterior margin on the epigynum. Biology. The species is native to Europe and has been apparently introduced into the Americas through human transport (Levi 1974a). The web was described

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by Wiehle (1931) in Germany, where he observed many examples built on iron gratings, walls, and greenhouses, and especially on stables and sheds. The web has a highly variable number of radii, viz., 14–34 (most often 25–30), is coarsely meshed, and the radials converge to a point from which the signal thread extends through the free sector to the spider’s retreat. The division between the hub and the attachment zone is not well defined, but the free zone is distinct. The catching area of a mature female’s web may be up to 30 cm in width, but is more often 12–20 cm. Older spiders remain in the retreat during daylight hours and come to the hub at dusk. Young individuals may occupy the hub both day and night. Net repairs are made in early morning. A struggling prey in the web sets up vibrations which are transmitted to the spider; the spider captures the prey, bites it, then wraps it with silk. The spider may then return to the retreat for upwards of an hour before retrieving the prey, carrying it to the retreat, and feeding. Webs are sometimes seen with no free sector (Wiehle 1931). The signal thread must then pass to the retreat at an angle, this angle being 40° or more depending on the space available for its placement. Jones (1994) observed a correlation between the absence of sticky spiral in the vacant sector and the placement of the web over deep recesses such as those found among boulders or on cliff faces. This occasional departure from the normal web design, in which both signal thread and web surface are in the same plane, may offer some survival value from bird predation in certain habitats such as window frames and other such recesses, but the hypothesis needs testing. Behavioral studies on Z. x-notata include those on feeding (Le Guelte 1970, Leborgne et al. 1991, Pasquet et al. 1994), on the spider’s vibration receptors (Barth 1982), and on regulation of web density (Kremer 1989). Witt and Reed (1965, 1968) used individuals of this spider to study the effects of various drugs on web construction. As shown by Wiehle (1931), adults appear in the second half of July and persist until late autumn. Some females in protected situations such as greenhouses may survive until the following spring. Eggs are normally laid in autumn and hatch the following April, but Spiller (1993) observed hatching in the same season as maturity of the parents in some California individuals. Blanke (1986) described courtship and mating.

Zygiella dispar (Kulczy½ski) Figs. 711–718; Map 86

Zygiella dispar Kulczy½ski, 1885:24, figs. 7a–7d (pl. 9); Gertsch 1964:7, figs. 7–10; Levi 1974a:278, figs. 33–37, 44, 48.

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Figs. 711–718. Zygiella dispar. 711–714, 716, epigynum: 711, 712, ventral views; 713, 714, 716, posterior views; 715, spermathecae; 717, 718, palpus of male: 717, retrolateral view; 718, median apophysis.

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Map 86. Collection localities of Zygiella dispar.

Male. Total length 6.20 ± 0.76 mm; carapace 3.00 ± 0.51 mm long, 2.59 ± 0.41 mm wide (10 specimens measured). Carapace pale orange to dark orange, sparsely covered with short pale recumbent setae, with single row of curved erect setae along lateral margins. Sternum yellowish to black, paler mesally. Legs pale orange, with tips (and sometimes bases and middle areas) of femora, patellae, tibiae, and basitarsi darkened, and with dark spots at bases of macrosetae. Abdomen gray or silvery, with pattern of connected black spots along margins. Palpus (Figs. 717, 718) with 1 long macroseta on patella, 1 to several on tibia; tibia much shorter than cymbium; paracymbium flattened, with minute excavation at tip; tegulum with stout pointed process; median apophysis with 12 or more minute teeth on ridge; embolus long, slender distally, curving over tip of genital bulb and extending basally nearly one-half length of bulb; terminal apophysis large, usually smoothly rounded over tip of bulb, lying parallel to embolus. Female. Total length 6.32 ± 0.66 mm; carapace 2.53 ± 0.26 mm long, 2.02 ± 0.22 mm wide (10 specimens measured). Coloration as in male, but dark pigment on legs often much more distinct. Epigynum (Figs. 711–714) prominent, well sclerotized, rugose, with distinct anterior rim, lacking paired prominences

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laterally; median septum broad, somewhat concave, narrowed posteriorly to approximately one-half its greatest width; spermathecae round, separated by approximately twice the diameter of one of them (Figs. 715, 716). Range. Southern Alaska to California, on or near the Pacific coast; northeast Asia. Comments. Males of Z. dispar are distinguished from those of other Canadian species of Zygiella by the large number of minute teeth on the ridge of the median apophysis; males are also significantly larger than those of Z. nearctica in total length and in carapace length and width (p < 0.01 for samples of 10 specimens). Females are distinguished by the distinct anterior rim of the epigynum (easily detected by drawing the tip of a needle across it); females are significantly larger than those of Z. nearctica on total length and on carapace length and width (p < 0.01 for samples of 10 specimens). Whether Z. dispar as treated here is conspecific with the Russian population is a problem requiring further study. Biology. Most specimens of Z. dispar have been collected from the foliage of coniferous trees. One collection was made on a building in a forest clearing. Adult males were taken in June and July, and adult females from June to September.

Zygiella nearctica Gertsch Figs. 719–725; Map 87

Zygiella nearctica Gertsch, 1964:4, figs. 3–6. Zygiella dispar: Levi 1974a:272, figs. 32, 38–43, 45–47, 49, 50. Male. Total length 4.34 ± 0.29 mm; carapace 2.32 ± 0.16 mm long, 1.96 ± 0.13 mm wide (10 specimens measured). Carapace pale orange to dark orange, often darkened anterior to dorsal groove, sparsely covered with short pale recumbent setae, and with row of curved setae along lateral margins. Sternum yellowish to black, pale mesally. Legs yellowish to orange, usually darkened at base, middle, and tip of femora, patellae, tibiae, and basitarsi; with dark spot at base of each macroseta. Abdomen gray or off-white, with pattern of connected black spots along margins. Palpus (Figs. 723–724) with 1 dorsal macroseta on patella and 1 to several on tibia; tibia much shorter than cymbium; paracymbium flattened, with minute excavation at tip; tegulum with 2 short ventrally directed processes, the basal one pointed and the other somewhat flattened and bladelike; median apophysis small, with 7–9 short thick teeth (Fig. 725); embolus long, slender, curved over tip of genital bulb and extending approximately one-half length of bulb (Fig. 724); terminal apophysis large, usually arched angularly over tip of genital bulb, lying parallel to embolus.

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Figs. 719–725. Zygiella nearctica. 719–721, epigynum: 719, ventral view; 720, 721, posterior views; 722, spermathecae; 723–725, palpus of male: 723, retrolateral view; 724, ventral view; 725, median apophysis. cym, cymbium; e, embolus; ma, median apophysis; pc, paracymbium; pp, posterior plate; teg, tegulum.

Female. Total length 6.13 ± 1.19 mm; carapace 2.29 ± 0.23 mm long, 1.83 ± 0.15 mm wide (10 specimens measured). Coloration as in male. Epigynum (Figs. 719, 720) prominent, well sclerotized, rugose, with barely detectable anterior rim, and with pair of prominences laterally; median septum broad, somewhat concave, narrowed posteriorly to approximately one-half its greatest width; posterior plate vase-shaped; spermathecae round, separated by their diameter or less (Fig. 722). Range. Alaska to Newfoundland, south to Colorado and to North Carolina.

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Map 87. Collection localities of Zygiella nearctica.

Comments. Males of Z. nearctica are distinguished from those of other Canadian species of Zygiella by the two prominent processes on the tegulum, the distal one being flattened and bladelike. Males are significantly smaller than those of Z. dispar on total length and on carapace length and width. Females are distinct in having paired prominences on the epigynum and in having a low, barely detectable anterior rim on the epigynum. Females are significantly smaller than those of Z. dispar on total length and on carapace length and width (see under Z. dispar). Placement of this species in synonymy of Z. dispar by Levi (1974a) is here changed. Biology. Webs of Z. nearctica are built on coniferous trees and on shrubs, boulders, rocky cliffs, bridges, and buildings. Adults of both sexes have been collected from May to August.

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Genus Acanthepeira Marx in Howard Members of the genus Acanthepeira, as the generic name suggests, have spiny abdomens (Fig. 726), though the integument of this part of the body is rather soft. The webs are complete orbs of 15–25 cm diameter, and possess a nearly open hub, a free zone, and a retreat nearby where the spider spends the daytime. Description. Total length 4.9–15.5 mm. Carapace brownish, covered with short white setae, convex dorsally in anterior half; front 2–3 times as high as diameter of anterior median eyes or approximately equal to length of median ocular area. Eyes small; lateral eyes on each side situated on pointed tubercle (Fig. 726). Legs yellowish, with brown rings; coxa I of male lacking hook; coxa IV of male with blunt spur; tibia II of male not strongly modified in size or macrosetation. Abdomen brownish, with white or dark markings, with anteromedian tubercle, often with additional spines or tubercles (Fig. 726). Palpus of male (Figs. 731, 732) with 1 patellar macroseta; sclerites of genital bulb compact, facing midline, partly concealed by cymbium; tegulum large, occupying entire lateral surface of bulb; median apophysis small, club-shaped, without spurs; embolus long, with slender pointed tip, situated distally; terminal apophysis lacking, replaced by small paramedian apophysis. Epigynum (Figs. 728–730) broad at base, abruptly narrowed to short slender scape; scape smooth or with transverse ridges and grooves; posterior plate approximately heart-shaped; spermathecae large, elliptical, oblique, nearly touching (Fig. 727). Comments. Specimens of the genus Acanthepeira are distinguished from those of other araneid genera by the pointed lateral eye tubercles, by the lack of a terminal apophysis in the male palpus, and by the abruptly narrowed epigynum. The genus is represented only in North America, and Levi (1976) treated the four known species. One species is represented in Canada.

Acanthepeira stellata (Walckenaer) Starbellied Orbweaver Figs. 726–732; Map 88

Epeira stellata Walckenaer, 1805:65; Emerton 1885:319, figs. 17 (pl. 34), 3–5 (pl. 37). Epeira nobilis Walckenaer, 1841:119. Cyrtarachne dugesi O. Pickard-Cambridge, 1893:113. Acanthepeira stellata: Kaston 1948:234, figs. 714–716 (pl. 33), 734 (pl. 34), 2038 (pl. 120); Levi 1976:364, plate 3, figs. 12–23. Male. Total length 7.36 ± 0.69 mm; carapace 3.64 ± 0.32 mm long, 2.98 ± 0.18 mm wide (10 specimens measured). Carapace brown. Legs yellowish, with

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Figs. 726–732. Acanthepeira stellata. 726, female, dorsal view; 727, spermathecae; 728–730, epigynum: 728, ventral view; 729, lateral view; 730, posterior view; 731, 732, palpus of male: 731, ventral view; 732, mesal view. cym, cymbium; e, embolus; ma, median apophysis; teg, tegulum.

brown rings. Abdomen brown, with light and dark markings, with large conical median tubercle anteriorly, and with 4 or 5 lateral spines or tubercles; anterior pair of lateral tubercles double. Palpus with 1 patellar macroseta; median apoph310

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Map 88. Collection localities of Acanthepeira stellata.

ysis club-shaped (Fig. 732); embolus long, shaftlike, abruptly narrowed to slender curved point, largely concealed by cymbium (Figs. 731, 732). Female. Total length 11.42 ± 1.50 mm; carapace 4.11 ± 0.53 mm long, 3.69 ± 0.42 mm wide (10 specimens measured). Coloration and abdominal spines as in male (Fig. 726). Epigynum with base broader than long, abruptly narrowed to slender smooth scape (Figs. 728–730); spermathecae large, elliptical, nearly touching (Fig. 727). Range. Southern Manitoba to Nova Scotia, south to Arizona, Mexico, and Florida. Comments. Adults of A. stellata are distinguished from those of other araneid genera by the abruptly narrowed embolus tip and by the short slender epigynal scape. Biology. Individuals of A. stellata are found in deciduous trees and shrubs, in forage crops, and in tall grass and weeds. Lowrie (1953) thought them to be more tolerant of dry habitats than many orb weavers. According to Kaston (1948), juveniles overwinter and reach maturity the following May. Adults of both sexes live until autumn. Mature females can apparently capture and subdue quite large prey (Lockley 1990). 311

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Genus Larinia Simon Members of the genus Larinia are found in tall grass and weeds, and in the lower branches of trees. They can be collected by sweep net. Description. Total length 2.9–11.7 mm. Carapace elongate, usually with slender dark longitudinal band (Fig. 733). Posterior median eyes touching or nearly so (Fig. 733), and median ocular quadrangle more than twice as wide anteriorly as posteriorly. Sternum dark brown to black, sometimes pale mesally and black laterally (Fig. 734). Legs long, slender, lacking dark rings, sometimes with small black spots, in male without spurs, hooks, or specialized macrosetae. Palpcoxal lobe with ventral tooth at base. Abdomen elongate, extending anteriorly in blunt prominence over carapace and extending posteriorly beyond spinnerets (Fig. 733); dorsal pattern formed of slender longitudinal bands and rows of small black spots (Fig. 733); venter with broad median white band; band bordered with gray or black, sometimes subdivided by slender black band (Fig. 734). Palpus of male with 2 long patellar macrosetae; tegulum convex, triangular, occupying basal half of genital bulb; median apophysis short, thick, with 2 stout pointed spurs (Figs. 738, 739); embolus variously shaped, sometimes rod-shaped or ribbonlike, with tip that breaks off during mating and is left in copulatory tube of female; terminal apophysis large, curved over tip of genital bulb (Fig. 739). Epigynum with short broad scape; scape annulate or smooth, sometimes spoonshaped at tip (Fig. 735); spermathecae round or elliptical, touching or nearly so (Fig. 737). Comments. Members of the genus Larinia are distinguished from those of other araneid genera by the touching or nearly touching posterior median eyes, and by the broad median white band, sometimes subdivided by a slender black band, on the abdominal venter. The genus is represented in most continents, and Levi (1990) has estimated a world fauna of 30–40 species. There are three species in America north of Mexico (Levi 1975a), only one of which is represented in Canada.

Larinia borealis Banks Figs. 733–739; Map 89

Larinia borealis Banks, 1894:8; Kaston 1948:228, figs. 732, 733 (pl. 34); Levi 1975a:108, figs. 13–21, 32, 35, 42–44. Male. Total length 5.31 (4.73–5.81) mm; carapace 2.60 (2.41–2.99) mm long, 1.84 (1.73–1.90) mm wide (4 specimens measured). Carapace and legs yellowish. Dorsum of abdomen variable, usually with broad pale median band and with four pairs of small black streaks laterally (Fig. 733); venter black or nearly so, with pale median band subdivided by slender black band (Fig. 734). Embolus

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Figs. 733–739. Larinia borealis. 733, female, dorsal view; 734, abdomen of female, ventral view; 735, 736, epigynum: 735, ventral view; 736, posterior view; 737, spermathecae; 738, 739, palpus of male: 738, mesal view; 739, ventral view. cym, cymbium; e, embolus; ma, median apophysis; spt, spermatheca; term, terminal apophysis.

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Map 89. Collection localities of Larinia borealis.

slender, tapered to tip (Fig. 738); median apophysis large, with 2 strong spurs (Figs. 738, 739). Female. Total length 6.50 ± 0.79 mm; carapace 2.51 ± 0.30 mm long, 1.84 ± 0.23 mm wide (10 specimens measured). Coloration essentially as in male (Fig. 733). Epigynal scape broad, with posteriorly arched annulation; copulatory opening with mesal margin oblique (Figs. 735, 736). Spermathecae small, round, nearly touching (Fig. 737). Range. Southern Alberta and northern Washington to New Hampshire, south to California, northern Mexico, and Virginia. Comments. Specimens of L. borealis are distinguished from those of other species in the genus by the presence of paired black streaks on the posterior half of the dorsum, and by the angular mesal margin of the copulatory opening. Biology. Specimens of L. borealis have been collected from tall weeds and grasses, from shrubs, and from low tree branches.

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Genus Metepeira F.O. Pickard-Cambridge Members of the genus Metepeira are rather small orb weavers of forest trees and shrubs, bog plants, and orchards. The web, with about 35 radii and 25 or more sticky spirals, is sometimes incomplete in the upper half. Above and to one side of the web is an irregular tangle of threads called a barrier web, and there the spider builds its dense silken retreat. One to several signal threads connect the web’s hub, which is filled with thread, to the retreat. Description. Total length 3.5–8.5 mm. Carapace brownish, paler at anterior extremity (Figs. 740, 741), covered with white recumbent setae. Anterior median eyes equal to or somewhat larger than other eyes; posterior row of eyes straight or somewhat recurved. Legs short, stout, with alternating pale and dark rings, and with many long macrosetae (Figs. 740, 741),); coxa I of male lacking hook; basitarsus and distitarsus together longer than patella plus tibia. Abdomen short, ovoid or round, somewhat flattened dorsally, with series of paired triangular marks on pale background dorsally (Figs. 740, 741, 749, 758, 765); venter with longitudinal white median spot or band on black background (Figs. 742, 750, 759, 766). Palpus of male (Figs. 747, 748, 755, 756, 763, 770, 771) usually with 2 dorsal patellar macrosetae and usually with 2 tibial macrosetae; median apophysis short, thick, prominent, with 2 slender filamentlike spurs at base (Figs. 748, 757, 764, 772), often with toothed keel distally; embolus large, varying according to species; conductor small, often concealed by other sclerites; terminal apophysis bulbous, sometimes with 1 or more minute denticles at tip (Figs. 747, 756, 763, 771); paracymbium small, fingerlike, situated at base of cymbium. Epigynum (Figs. 743–745, 751–753, 760, 761, 767) small, with pointed curved scape; scape indistinctly ridged and grooved; posterior plate usually elongate, slender, sometimes shorter and broader; spermathecae round or elliptical, nearly touching (Figs. 746, 754, 762, 769). Comments. Representatives of Metepeira spp. are distinguished from those of most other araneid genera by the presence of a longitudinal white streak on the venter of the abdomen and by the filamentlike spurs on the base of the median apophysis. They resemble those of Aculepeira spp., but differ by having a shorter, more rotund abdomen, by having a pale area at the anterior end of the carapace, and by having a bulbous terminal apophysis. The genus Metepeira is represented only in North, Central, and South America. Levi (1977b) treated the eleven known species. Four species are known in Canada.

Key to species of Metepeira 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

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2(1).

Median apophysis with small smooth prominence at distal end (Fig. 747); sternum with pale median longitudinal band . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . labyrinthea (Hentz) (p. 317)

2'.

Median apophysis with large toothed keel at distal end (Figs. 757, 764, 772); sternum lacking pale median band . . . . . . . . . . . . . . . 3

3(2').

Embolus acutely angled (Fig. 757) . . . foxi Gertsch & Ivie (p. 320)

3'.

Embolus curved (Figs. 764, 772) . . . . . . . . . . . . . . . . . . . . . . . . . 4

4(3').

Leg coxae black; range transcontinental (Map 92) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . palustris Chamberlin & Ivie (p. 322)

4'.

Leg coxae pale; range from southern interior of British Columbia to southern Saskatchewan and southward (Map 93) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . grandiosa Chamberlin & Ivie (p. 324)

5(1').

Posterior plate of epigynum long, slender posteriorly (Fig. 744) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . labyrinthea (Hentz) (p. 317)

5'.

Posterior plate of epigynum shorter, more uniform in width (Figs. 752, 761, 768) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

6(5').

Atrium of epigynum little wider than long (Fig. 751) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . foxi Gertsch & Ivie (p. 320)

6'.

Atrium broader, distinctly wider than long (Figs. 760, 767) . . . . . 7

7(6').

Anterior margin of lateral sclerites oblique (Fig. 761); leg coxae black . . . . . . . . . . . . . . . . . . . palustris Chamberlin & Ivie (p. 322)

7'.

Anterior margin of lateral sclerites straight and transverse (Fig. 768); leg coxae yellowish brown . . grandiosa Chamberlin & Ivie (p. 324)

Clé des espèces de Metepeira 1.

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1'.

Femelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2(1).

Apophyse médiane munie au plus d’une petite bosse lisse à l’apex (fig. 747), sternum orné d’une bande longitudinale pâle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . labyrinthea (Hentz) (p. 317)

2'.

Apophyse médiane munie d’une proéminence dentée à l’apex (figs. 757, 764, 772); sternum sans bande longitudinale pâle . . . . 3

3(2').

Embolus formant un angle aigu (fig. 757) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . foxi Gertsch & Ivie (p. 320)

3'.

Embolus recourbé (figs. 764, 772) . . . . . . . . . . . . . . . . . . . . . . . . 4

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4(3').

Coxas des pattes noires, distribution transcontinentale (Carte 92) . . . . . . . . . . . . . . . . . . . . . . . . palustris Chamberlin & Ivie (p. 322)

4'.

Coxas des pattes pâles, distribution s’étendant du sud-est de la Colombie Britanique jusqu’au sud de la Saskatchewan, et plus au sud au État-Unis (Carte 93) . . . . grandiosa Chamberlin & Ivie (p. 324)

5(1').

Bordure de la plaque postérieure de l’épigyne évasée, plus large dans la partie postérieure que dans la partie antérieure (fig. 744) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . labyrinthea (Hentz) (p. 317)

5'.

Bordure de la plaque de l’épigyne presque parallèle, plus courte et de largeur uniforme (figs. 752, 761, 768) . . . . . . . . . . . . . . . . . . . . . . 6

6(5').

Atrium de l’épigyne un peu plus large que long (fig. 751) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . foxi Gertsch & Ivie (p. 320)

6'.

Atrium de l’épigyne nettement plus large que long (figs. 760, 767) ...................................................7

7(6').

Marges antérieures des sclérites latéraux obliques (fig. 761), coxas des pattes noires . . . . . . . . . . palustris Chamberlin & Ivie (p. 322)

7'.

Marges antérieures des sclérites latéraux droite (fig. 768); coxas des pattes brun-jaunâtre . . . . . . . grandiosa Chamberlin & Ivie (p. 324)

Metepeira labyrinthea (Hentz) Labyrinth Orbweaver Figs. 740–748; Map 90

Epeira labyrinthea Hentz, 1847:471, fig. 3 (pl. 31); Emerton 1885:314, figs. 8 (pl. 34), 11 (pl. 36). Epeira crucifera Keyserling, 1864:132, figs. 11, 12 (pl. 6). Name preoccupied in genus Epeira. Metepeira labyrinthea: F.O. Pickard-Cambridge 1903:458, figs. 6, 7 (pl. 43); Chamberlin and Ivie 1942:63, figs. 161–164; Kaston 1948:226, figs. 704 (pl. 33), 724 (pl. 34), 2036 (pl. 119); Levi 1977b:196, plate 1, figs. 1–11, 14–20. Aranea keyserlingi Roewer, 1942:861. New name for Epeira crucifera Keyserling, preoccupied. Male. Total length 4.31, 4.65 mm; carapace 2.27, 2.49 mm long, 1.66, 1.70 mm wide (2 specimens measured). Carapace brownish, with anterior extremity pale (Fig. 741). Legs yellowish brown, with dark pigment at tips of most segments; femur I with double row of macrosetae ventrally, and femora II-IV with single row of macrosetae (Fig. 741). Sternum with pale midstripe. Abdomen with paired dark triangular marks in anterior half and with dark transverse bars poste-

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Figs. 740–748. Metepeira labyrinthea. 740, female, dorsal view; 741, male, dorsal view; 742, abdomen of female, ventral view; 743–745, epigynum: 743, ventral view; 744, posterior view; 745, lateral view; 746, spermathecae; 747, 748, palpus of male: 747, mesal view; 748, ventral view. cym, cymbium; ma, median apophysis.

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Map 90. Collection localities of Metepeira labyrinthea.

riorly (Fig. 741); venter with white midstripe (Fig. 742). Palpus (Figs. 747, 748) with 2 long slender macrosetae on patella, and with 2 similar macrosetae on tibia; median apophysis with 2 large curved filamentlike spurs, and with small smooth distal prominence; embolus flanked by 2 broad flat processes. Female. Total length 6.31 (4.98–7.55) mm; carapace 2.66 (2.24–3.15) mm long, 2.19 (1.88–2.57) mm wide (4 specimens measured). Coloration as in male, but leg pigmentation and abdominal spots and bars more distinct (Figs. 740, 742). Epigynum (Figs. 743–745) with broad tapered scape and round copulatory openings; scape somewhat constricted at base; posterior plate long, slender, with anterior margin farther posterior than anterior margin of lateral sclerites; spermathecae small, round (Fig. 746). Range. Wisconsin and southern Ontario to Massachusetts, south to Texas, northeastern Mexico, and Florida. Comments. Males of M. labyrinthea are distinguished from those of other species in the genus by the small smooth prominence on the median apophysis. Females are distinguished by the long slender posterior plate of the epigynum. Biology. Individuals of M. labyrinthea inhabit the shrub understorey of deciduous forests. Adult males are present from late July to August, and adult females from late July to late autumn. Females make five or six papery egg sacs and place them in a vertical chain near the web (Kaston 1948); the early sacs pro-

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duce spiderlings in autumn, but later sacs retain the young until the following spring.

Metepeira foxi Gertsch & Ivie Figs. 749–757; Map 91

Metepeira foxi Gertsch and Ivie, 1936:20, figs. 42–44; Chamberlin and Ivie 1942:71, figs. 197, 198; Levi 1977b:210, figs. 87–96. Metepeira nanella Chamberlin and Ivie, 1942:71, fig. 199.

Map 91. Collection localities of Metepeira foxi.

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Figs. 749–757. Metepeira foxi. 749, 750, female: 749, dorsal view; 750, ventral view; 751–753, epigynum: 751, ventral view; 752, posterior view; 753, lateral view; 754, spermathecae; 755–757, palpus of male: 755, mesal view; 756, ventral view; 757, embolus and median apophysis. atr, atrium.

Male. Total length 3.44 (2.91–4.48) mm; carapace 1.60 (1.41–1.74) mm long, 1.27 (1.04–1.70) mm wide (4 specimens measured). Carapace brownish, with pale anterior extremity. Sternum black. Legs brownish, with darker areas at 321

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distal ends of most segments; coxae pale. Abdomen pale, with paired indistinct triangular areas dorsally; venter black, with distinct white midstripe. Palpal patella and tibia each with 2 long slender macrosetae dorsally; median apophysis with rugose prominence at distal end (Fig. 757); embolus with single supporting prominence, and distal part forming acute angle with base (Fig. 755, 756). Female. Total length 4.93 ± 0.62 mm; carapace 1.92 ± 0.17 mm long, 1.54 ± 0.20 mm wide (10 specimens measured). Coloration as in male, but abdominal and leg markings more distinct (Figs. 749, 750). Epigynum with short tapered scape and elongate copulatory openings (Figs. 751, 753); posterior plate short, rather broad, with anterior margin situated posterior to anterior margin of lateral plates (Fig. 752); spermathecae elliptical (Fig. 754). Range. Southern British Columbia and southern Alberta to southern California and northwestern Mexico. Comments. Specimens of M. foxi are distinguished by the acutely angled embolus and by the short broad posterior plate of the epigynum. Biology. Individuals of M. foxi commonly build their webs in sage brush and in meadow plants between trees (Levi 1977b).

Metepeira palustris Chamberlin & Ivie Figs. 758–764; Map 92

Metepeira palustris Chamberlin and Ivie, 1942:73, figs. 208–210. Metepeira grandiosa palustris: Levi 1977b:212, figs. 97, 98, 101–105. Male. Total length 4.20 ± 0.52 mm; carapace 2.02 ± 0.31 mm long, 1.62 ± 0.24 mm wide (10 specimens measured). Carapace dusky brown, somewhat paler

Map 92. Collection localities of Metepeira palustris.

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Figs. 758–764. Metepeira palustris. 758, 759, female: 758, dorsal view; 759, ventral view; 760, 761, epigynum: 760, ventral view; 761, posterior view; 762, spermathecae; 763, 764, palpus of male: 763, mesal view; 764, embolus and median apophysis. atr, atrium; e, embolus; ls, lateral sclerite.

anteriorly, sometimes with pale band along midline. Sternum black. Legs yellowish, with coxae black, and with other segments black or dark brown distally; femur I with cluster of about 7 long dark macrosetae prolaterally distal to middle. Abdomen rounded to ovoid, highest anteriorly; grayish, with pattern of paired white and black spots and streaks; venter black, with median white spot or band, and with pair of white spots posteriorly. Palpal patella and tibia each with 1 or 2 strong macrosetae; median apophysis with 2 long filamentous spurs and with large toothed keel (Figs. 763, 764); conductor semilunar (ventral view); terminal apophysis bulbous, with sclerotized tip extending over tip of embolus (Fig. 763); embolus angled at approximately 90° (Figs. 763, 764), with or without cap. 323

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Female. Total length 5.55 ± 0.83 mm; carapace 2.39 ± 0.28 mm long, 2.04 ± 0.30 mm wide (10 specimens measured). Coloration as in male (Figs. 758, 759). Epigynum with broad tapered scape (Fig. 760); atrium broader than long, rather shallow; posterior plate rather broad, with distinct curved or sinuous anterior margin (Fig. 761); lateral sclerites with oblique anterior margins (Fig. 761); copulatory tubes thick, curved; spermathecae elliptical, nearly touching (Fig. 762). Range. Northern British Columbia to Nova Scotia and Maine, south to Wisconsin and northern Pennsylvania. Comments. Levi’s (1977b) placement of M. palustris as a subspecies of M. grandiosa is here replaced by full species rank for both M. palustris and M. grandiosa (see comments on M. grandiosa). Individuals of M. palustris differ from those of other species of Metepeira except M. foxi and M. grandiosa by the broad distal keel on the median apophysis and by the broad shallow atrium. Males of M. palustris differ from those of M. foxi in having a less angulate embolus, and from those of M. grandiosa in having a more slender embolus and more distinctly marked body and legs. Females of M. palustris differ from those of M. foxi in having a longer posterior plate in the epigynum, and from females of M. grandiosa in having oblique anterior margins on the lateral sclerites of the epigynum. Specimens of both sexes of M. palustris are significantly larger than those of M. grandiosa in the Central Plains, where populations of these species cooccur (p < 0.01 for samples of 10 specimens). Biology. Specimens of M. palustris have been swept from bog plants and ferns in eastern Canada, and from prairie herbs and shrubs in the Central Plains. Males are collected in the second half of July, and females from late July to midSeptember. Females with egg sacs were collected on 5 August and 8 September.

Metepeira grandiosa Chamberlin & Ivie Figs. 765–772; Map 93

Metepeira grandiosa Chamberlin and Ivie, 1941:17, figs. 24–26; Levi 1977b:210. Metepeira palomara Chamberlin and Ivie, 1942:72, figs. 200–204. Metepeira dakota Chamberlin and Ivie, 1942:73, figs. 205–207. Metepeira alpina Chamberlin and Ivie, 1942:74. Metepeira grandiosa grandiosa: Levi 1977b:214, figs. 112–116; Piel 2000:23, figs. 22–28, 301. Metepeira grandiosa alpina: Levi 1977b:212, in part, figs. 99, 100, 106–111; Piel 2000:24, figs. 29–35, 325. Male. Total length 3.12 ± 0.32 mm; carapace 1.55 ± 0.10 mm long, 1.25 ± 0.11 mm wide (10 specimens measured). Carapace yellowish brown, paler ante324

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Figs. 765–772. Metepeira grandiosa. 765, 766, female: 765, dorsal view; 766, ventral view; 767, 768, epigynum: 767, ventral view; 768, posterior view; 769, spermathecae; 770–772, palpus of male: 770, mesal view; 771, ventral view; 772, embolus and median apophysis.

riorly and along midline. Sternum black. Legs yellowish, sometimes with dark pigment at distal ends of segments, and with coxae yellowish or brownish; femur I with cluster of about 7 long macrosetae prolaterally. Abdomen grayish or brownish, with pattern of paired black spots and streaks (as in Fig. 765); venter black, with white median band, and with pair of white spots posteriorly (Fig. 766). Palpal patella and tibia each with 2 strong macrosetae; tegulum occupying basal half of genital bulb; median apophysis rounded mesally, with toothed 325

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Map 93. Collection localities of Metepeira grandiosa.

keel distally, and with 2 prominent curved filaments (Figs. 770–772); conductor thin, flat, triangular or semilunar in ventral view; terminal apophysis bulbous except for sclerotized tip, which arches over tip of embolus; embolus with or without cap, enlarged and approximately elliptical in basal half, abruptly curved at midlength, more slender distally (Figs. 770, 772). Female. Total length 3.12 ± 0.32 mm; carapace 1.55 ± 0.10 mm long, 1.25 ± 0.11 mm wide (10 specimens measured). Coloration as in male (Figs. 765, 766). Epigynum with scape; scape short, broad at base, slender distally, projecting ventrally (Fig. 767); atrium broad, rather shallow, with copulatory openings situated at lateral extremities; posterior plate rather broad, with distinct curved or somewhat sinuous anterior margin; lateral sclerites with transverse anterior margins 326

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(Fig. 768); copulatory tubes thick, curved; spermathecae elliptical, nearly touching (Fig. 769). Range. Interior British Columbia to southern Saskatchewan, south to California. Comments. Levi (1977b) envisioned a single species, M. grandiosa, as representing five of Chamberlin and Ivie’s (1941, 1942) species of Metepeira from western United States (see synonymy). Levi further proposed three subspecies as representing M. grandiosa, namely, M. grandiosa grandiosa in westernmost United States and interior British Columbia, M. grandiosa alpina in the Rocky Mountains and the Central Plains, and M. grandiosa palustris in a narrow transcontinental band from northern British Columbia to Nova Scotia (Levi 1977b, map 2). In recent years, however, Donald J. Buckle and his colleagues in southern Alberta and southern Saskatchewan found abundant co-existent populations of M. grandiosa dakota (a junior synonym of M. grandiosa alpina in Levi’s 1977b classification) and M. grandiosa palustris at Suffield, Alberta. Both sexes were distinct on external genitalia and size, and there were no intermediates in the collections. Total length of the body, and length and width of the carapace, were significantly different, and the dates of maturity also differed. Specimens from interior British Columbia and western United States were also studied; Buckle and his colleagues inferred that two species could be defined, namely, M. grandiosa, which is widespread and variable in size and phenology, and M. palustris, which is transcontinental in a narrow band and is more restricted in size and phenology. This is the arrangement adopted here. Individuals of M. grandiosa differ from those of other species of Metepeira except M. foxi and M. palustris by the broad distal keel on the median apophysis and by the broad shallow atrium. Males of M. grandiosa differ from those of M. foxi in having a less angulate embolus, and from those of M. palustris in having a thicker embolus and paler body and legs. Females differ from those of M. foxi and M. palustris in having transverse anterior margins of the epigynal lateral sclerites. The body and legs are much paler than those of M. palustris. Individuals of both sexes are significantly smaller than those of M. palustris in areas where representatives of both species occur (see under M. palustris), but in southern British Columbia and western United States, where specimens of M. palustris do not occur, individuals of M. grandiosa tend to be larger and more variable in size than those on the Central Plains. Biology. Specimens of M. grandiosa have been swept from prairie herbs and shrubs on the Central Plains, and from sage brush or herbs in montane meadows in interior British Columbia and western United States. Males and females are mature from early April to early September, except in interior British Columbia and the Central Plains, where maturity is attained in June and July. 327

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Family Theridiosomatidae These small spiders superficially resemble the Theridiidae, and many of the species were originally described in that family. Since the beginning of the twentieth century, most workers have classified the theridiosomatids as a subfamily of Araneidae in recognition of the orb webs they build and the lack of a true tarsal comb on legs IV. Coddington (1986c) revised the group, assigning full familial status to it. Members of the family Theridiosomatidae inhabit humid spaces near the ground in shady forests, gorges, or cave entrances. Those that establish “tension lines” from the hub of the web to a nearby plant stem or similar object grip the hub region of the web with legs III and IV and draw the web into a cone with their powerful legs I and II. The spiders exert considerable force in tensioning the web, and can apparently hold their prey-ready posture “for hours at a time” (Coddington 1986c). Description. Total length 0.5–3.0 (usually less than 2.5 mm). Carapace glabrous or with a few scattered erect setae, pear-shaped, approximately as long as wide, often higher anteriorly than posteriorly (Fig. 773). Eyes subequal in size; lateral eyes on each side touching; posterior row of eyes straight or procurved. Sternum smooth or with minute papillae, and with paired pits at anterior margin (Fig. 774). Legs I and II stouter than III and IV; tarsi with irregular row of serrate setae ventrally; tibiae III and IV with 3 or 4 rows of long trichobothria. Abdomen soft, with few setae, subspherical or broadly elliptical, sometimes with tubercles, usually higher than long or wide, attached to cephalothorax near the abdominal midpoint (and hence broadly overhanging carapace), often with pattern of silvery blotches or bands (Fig. 773). Palpus of male (Figs. 777, 778) with hooked or Tshaped paracymbium; tegulum large, bulging, situated laterally; median apophysis situated mesally near base of genital bulb; embolus situated distally, broad and flat or tubelike, often with variously developed apophyses; seminal duct with complex trajectory within tegulum. Epigynum (Fig. 775) usually flat or domed, strongly sclerotized, with median pit, rarely with small scape; spermathecae small, usually rounded, usually touching (Fig. 776). Comments. Members of the family Theridiosomatidae are distinguished from those of other families of orb weavers by the possession of sternal pits, by the complex trajectory of the seminal duct, and by the presence of 3 or 4 rows of long trichobothria on tibiae III and IV. The family appears to occupy a basal position among the symphytognathoid groups, which together represent “a reduction series from the original araneoid ground plan” (Coddington 1990a). The family Theridiosomatidae comprises an estimated 12 genera and 71 species in the world. The members are largely cosmotropical, but two species, Theridiosoma epeiroides Bösenberg and Strand of southeast Asia and T. gemmosum (L. Koch) of Europe and North America, extend into the north temperate zone.

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Genus Theridiosoma O. Pickard-Cambridge Members of the genus Theridiosoma make small regular orb webs having few radii and widely spaced sticky spirals. They also make extra turns at the hub after the sticky spirals are in place, and some of the radii are then joined by anastomosis, i.e., joined before they reach the hub. A tension line is placed between the point at which the main web radii come together and some nearby object, and this is used in prey capture (see earlier section entitled “Nature of orb webs”). Description. Total length 0.5–2.5 mm. Carapace smooth, without prominences, abruptly narrowed anteriorly to approximately one-half maximum width, dark brown to light tan, rarely with darker markings in eye area. Anterior median eyes separated by approximately one-half their diameter, and posterior median eyes separated by the same distance or less. Legs rather short, tan in color, with few slender macrosetae; tibiae with cluster of long dorsal trichobothria, and basitarsi I–III with single long dorsal macroseta near base; legs I and II stouter than III and IV (Fig. 774). Abdomen dark, elliptical. Palpus of male with embolus subdivided into several long slender parallel tines (Fig. 778); median apophysis curved, lobelike, becoming slender distally, with shallow groove along distal surface. Epigynum (Fig. 775) usually with flat or domed plate, with or without scape; copulatory tubes broad, extending anteriorly then mesally; spermathecae small, rounded (Fig. 776). Comments. Members of the genus Theridiosoma are distinguished from those of other theridiosomid genera by the subdivision of the embolus into several slender parallel tines, by the curved lobelike median apophysis, and by the broad copulatory tubes. The genus comprises a world fauna of perhaps 30 species, of which only T. gemmosum is represented in Canada.

Theridiosoma gemmosum (L. Koch) Figs. 773–778; Map 94

Theridium gemmosum L. Koch, 1877:26, 69, figs. 2, 6–8. Theridiosoma argenteolum O. Pickard-Cambridge, 1879:194, figs. 8a– 8g. Theridiosoma gemmosum: Simon 1881:26, fig. 11 (pl. 26); Wiehle 1931:131, figs. 210–217; Kaston 1948:262, figs. 831–833 (pl. 40); Roberts 1985:222, fig. 100d; Coddington 1986c:64, figs. 6–9, 134, 149, 157–160. Theridiosoma argentatum Keyserling, 1886:218, fig. 132. Male. Total length 1.82 ± 0.15 mm; carapace 0.82 ± 0.08 mm long, 0.83 ± 0.06 mm wide (10 specimens measured). Carapace greenish tan, with a few dark streaks radiating from dorsal groove. Anterior lateral eyes and posterior lateral eyes touching, situated at lateral margins of carapace. Legs tan, with segments darkened at tips. Abdomen broadly elliptical in dorsal view, with dark blotches

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Figs. 773–778. Theridiosoma gemmosum. 773, female, lateral view; 774, cephalothorax of female, ventral view; 775, epigynum, ventral view; 776, spermathecae; 777, 778, palpus of male: 777, subapical view; 778, mesal view. con, conductor; e, embolus; ma, median apophysis; spt, spermatheca.

interrupted by many white dots. Palpus (Figs. 777, 778) with nearly spherical genital bulb; conductor large, lacking apophyses, produced distally into strong point; embolus partly concealed in unexpanded bulb, composed of slender parallel tines. 330

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Map 94. Collection localities of Theridiosoma gemmosum.

Female. Total length 2.35 ± 0.25 mm; carapace 0.81 ± 0.06 mm long, 0.77 ± 0.06 mm wide (10 specimens measured). Coloration essentially as in male (Fig. 773). Epigynum smoothly domed and hoodlike in posterior view (Fig. 775), strongly protuberant in lateral view (Fig. 773); spermathecae as in Fig. 776. Range. Minnesota to Newfoundland, south to Alabama and Florida; Europe, Asia. Coddington (1986c) puts forth the view that T. gemmosum is native to eastern North America and has been introduced into Eurasia. The difference in habitats in the two regions speaks against this view. Comments. Specimens of T. gemmosum can be distinguished from those of other species in the genus by the large unadorned conductor of the male palpus and by the strongly protuberant hooklike epigynum. Biology. Individuals build their webs in dark damp ravines or swamps, or on wet cliff faces and overhanging stream banks (Coddington 1986c). Those in the northern parts of the range are thought to winter in the penultimate instar and to mature early the following spring. The young may reach penultimate stage by 331

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autumn of the same year, then hibernate. The web was described by Wiehle (1931), and the egg sacs by Wiehle (1931) and Scheffer (1904a). The sacs, which Scheffer describes as “the most interesting to be found”, are golden brown spheres nearly 3 mm in diameter, suspended by a single thread nearly 2.5 cm long. The surface of the sac is papery and, at hatching time, the young spiderlings emerge through a circular slit that extends nearly the whole circumference of the sac near its point of attachment. The empty sac is often more easily found than the spider, and, because it persists through the summer, may be collected as vouchers for the presence of T. gemmosum.

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Glossary abdomen The posterior body division of a spider, connected to the cephalothorax by the pedicel. aciniform gland One of the multiple silk-producing glands opening on the posterior median and posterior lateral spinnerets; its silk is used in silk retreats, prey wrapping, and possible egg sacs. aggregate gland One of the paired silk glands opening on the posterior lateral spinnerets, which produces the gluey coating found on threads of the sticky spirals. ampullate gland One of the paired silk glands opening on the anterior lateral spinnerets (major ampullate) or on the posterior median spinnerets (minor ampullate), which produces drag lines and frame threads. anal tubercle A small prominence at the tip of the abdomen; the anus is situated on its ventral surface. annulation Ridges, usually transverse, on the scape of the epigynum in some orb-weaving spiders. anterior Pertaining to the foremost end of the body or to one of its main divisions. anteriorly Toward the foremost end of the body. anterodorsal Pertaining to the anterior end of the body and to the dorsal surface. anterolateral Pertaining to the anterior end of the body and to one side. anterolaterally Toward the anterior end of the body and to one side. anteromesal Pertaining to the anterior end of the body and to the midline. anteromesally Toward the anterior end of the body and the midline. apical Pertaining to the apex, or tip. apophysis A spine found on the male chelicerae or legs and usually having a sexual function. appressed Lying flat against the body or against one of its appendages. atrium A cavity in the epigynal plate having the copulatory openings of the female in its floor or wall; it may be subdivided by a median septum. attachment zone A circular area immediately outside the hub of an orb web where the radial threads are attached. auxiliary spiral The temporary spiral thread laid down by an orb-weaving spider after the radial threads are in place. The auxiliary thread is taken down as the sticky spiral is made. axial thread The core of the catching threads in cribellate webs. ballooning The transport of spiders through the air on a thread borne on air currents. basal Pertaining to the base of an appendage or segment.

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basal lamella One of the paired flat lobes at the side of the epigynum in some orb-weaving spiders. basally Toward the base of an appendage or segment. basitarsus The basal subdivision of the spider’s leg tarsus; called metatarsus by many authors. bifid Subdivided into two parts. bilobed Subdivided into two lobes. bipartite Same as bifid. book lung One of the paired booklike respiratory organs near the anterior end of the abdominal venter. bridge thread The uppermost thread of an orb web upon which the radial and spiral threads depend. calamistrum A series of stiff curved setae of uniform length along the dorsal surface of basitarsus IV in cribellate spiders; may be in one or two rows. cap A lightly sclerotized cone-shaped or scalelike structure covering the embolus tip in some virgin male orb-weaving spiders and sometimes left as a plug in the epigynums of their mates. carapace The dorsal plate of the cephalothorax, bearing the eyes and the dorsal groove, and representing the fused dorsal plates of the cephalothoracic segments. catching spiral The sticky spiral of orb webs. cephalothorax The undivided head–thorax, or anterior body region, to which are appended the chelicerae, palpi, and legs. chelicera (pl., chelicerae) One of the paired seizing and pinching organs hanging down at the anterior end of the cephalothorax; each comprises a large basal segment and a movable fang with, internally, the associated venom gland and muscles. They arise between the mouth and palpi in the early embryo, but move anterior to the mouth and rostrum during embryonic development. claw A short, curved, usually toothed process at the tip of the pretarsus of a leg or palpus. colulus A small median sclerite or soft lobe on the venter of the abdomen situated in the membranous area between the bases of the anterior pair of spinnerets. conductor A structure in the male palpus on which the terminal part of the embolus rests; although primitively part of the distal region of the genital bulb along with the embolus and terminal apophysis, the conductor can also be a secondary structure derived from the tegulum. copulatory opening One of the paired openings into which the embolus enters during copulation. copulatory tube One of the paired tubes leading inward from the copulatory openings of the female and receiving the embolus in copulation.

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coxa (pl., coxae) The first or most basal segment of a leg or palpus. coxal hook A sclerotized hook found on the coxa of leg I of some male orb weavers by which legs I and II are locked together during copulation. crepuscular Active mainly or only at twilight. cribellate Pertaining to spiders in which the abdomen has a cribellum. cribellum A transverse, platelike spinning organ on the venter of the abdomen anterior to the spinnerets. cylindrical gland One of the paired silk-producing glands opening on the posterior median and posterior lateral spinnerets of female orb weavers; also known as tubuliform gland. The silk is probably used in egg sac construction. cymbium The tarsus of the male palpus, cupping the alveolus and the genital bulb on its ventral surface. denticle A small tooth. distal Pertaining to the tip of an appendage or organ. distally Toward the tip of an appendage or organ. distal haematodocha A membranous sac at the base of the embolus and its associated structures; it fills with haemolymph, thus forcing the embolus into the female's copulatory opening. distitarsus The distal subdivision of the leg tarsus. distomesal Pertaining to the tip and the midline of an appendage or organ. diurnal Day active. dorsal Pertaining to the uppermost surface of the body or of an appendage or organ. dorsal groove A median furrow on the carapace marking an ingrowth of the body wall on which the dilator muscles of the sucking pump are attached. dorsally Toward the uppermost surface of the body or of an appendage or organ. dorsum The dorsal surface of the body or of the abdomen alone. drag line The thread spun by spiders when moving over the substrate. ecribellate Pertaining to spiders in which the abdomen has no cribellum. embolar apophysis An apophysis on the embolus. embolar scale A sclerotized scale on the embolus of some orb-weaving spiders; it may be attached to the copulatory opening of the female in mating. embolus The intromittent, or inserting, organ of the male palpus. epigynum The copulatory organ of female spiders situated at the midline immediately anterior to the genital groove; usually with a sclerotized plate in which the copulatory openings are found. fang The distal, piercing segment of the chelicera. fang furrow A depression along the mesal surface of the chelicera; it receives the fang when the latter is not in use. femur The third from the base and usually longest segment of a leg or palpus.

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fertilization tube One of the paired tubes by which semen stored in the spermathecae of the female is conveyed to the eggs as they pass out of the body. filamentous Slender and elongate. flagelliform gland One of the paired silk-producing glands opening on the posterior lateral spinnerets; its silk forms the core fibre of the threads forming the sticky spiral in ecribellate orb weavers. frame thread The threads attaching the radial and spiral threads of an orb web to objects in the surroundings. free zone An area of the orb web lying outside the attachment zone and crossed by no spiral threads. front That part of the carapace situated between the anterior margin and the anterior row of eyes genital bulb The male copulatory apparatus lying within the alveolus of the palpal cymbium. genital groove A transverse groove on the venter of the abdomen in which lie the openings of the internal genitalia (ovaries or testicles) and a pair of book lungs. glabrous Smooth; free of setae. haematodocha An inflatable sac that extends and rotates the sclerotized parts of the genital bulb into copulatory position when filled with haemolymph from the body cavity. haemolymph Spider blood. hood A pocketlike cavity at the anterior end of the epigynum. hub The innermost circle of the orb web; may be filled with threads or vacant. keel A ridge. labium The lower lip, which closes the mouth behind; it develops from the sternum of the palpal segment in the spider embryo. lamella A sclerotized process arising at the base of one of the parts of the male palpus. lateral Pertaining to the side. laterally Toward the side. lateral sclerite One of the paired flat sclerites situated lateral to the posterior plate of the epigynum; usually viewed posteriorly. longitudinal Parallel to long axis of the body or of an appendage. macroseta An erectile seta arising from a membranous area on the legs and palpi. mating thread A thread spun by a courting male orb weaver between the female’s web and a nearby object; the female, if receptive, climbs upon it preparatory to mating. 336

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median Pertaining to the middle. median apophysis An appendage of the tegulum on the genital bulb of the male palpus. median septum A raised median longitudinal ridge on the floor of the epigynal atrium. mesal Pertaining to the midline. mesally Toward the midline. midline An imaginary line dividing the body or an appendage into right and left halves. orb web The flat web of orb-weaving spiders; a completed orb comprises a bridge thread, frame threads, radial threads, and spiral threads; a stabilimentum is added by some spiders. oviduct A tube carrying the unfertilized eggs from the ovary to the fertilization tube. palp-coxal lobe One of the paired lateral lobes on the mesal surface of the palpal coxae; called endites by many workers. palpus One of the paired leglike appendages situated between the mouth and the first pair of legs; in adult male spiders, modified as a semen-storing and copulatory organ. papillae Cuticular outgrowths, usually smaller than spurs or tubercles. paracymbium An apophysis usually situated at the base of the cymbium of the male palpus. paramedian apophysis A small sclerite situated at the base of the embolus in some male orb weavers, e.g., Acanthepeira stellata. patella The fourth segment from the base of a leg or palpus, rigidly connected to the tibia. pedicel The slender flexible connection between the cephalothorax and the abdomen. piriform gland One of a cluster of silk-producing glands opening on the anterior lateral spinnerets; its silk attaches drag lines to the substrate at intervals. posterior Pertaining to the hindmost end of the body or of one of its main divisions. posterior plate A median sclerite situated between the lateral sclerites in the posterior part of the epigynum. posteriorly Toward the hindmost end of the body or of one of its main divisions. posterolateral Pertaining to the posterior and the side. pretarsus The seventh, or terminal, segment of a leg or palpus; it bears the claws. procurved The anterior displacement of the ends of a transverse, otherwise straight or procurved, row of eyes. prolateral Pertaining to the lateral surface of a leg or palpus nearest the anterior end of the body when the limb is extended at a right angle to the midline. 337

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prolaterally Toward the lateral surface of a leg or palpus nearest the anterior end of the body when the limb is extended at a right angle to the midline. promargin The anterior margin of the cheliceral fang furrow. pseudoflagelliform gland One of the paired silk glands opening on the posterior lateral spinnerets; its silk forms the core fibre of the sticky spiral thread in the Uloboridae. radial thread One of the threads extending form the hub to the frame threads; their placement follows that of the bridge thread and precedes that of the auxiliary spiral. radix A small sclerite interposed between the tegulum and the base of the embolus. recurved The posterior displacement of the ends of a transverse, otherwise straight or procurved, row of eyes. reservoir The storage vessel for semen in the male spider’s palpus. retrolateral The lateral surface of a leg or palpus nearest the posterior end of the body when the limb is extended at a right angle to the midline. retrolaterally Toward the lateral surface of a leg or palpus nearest the posterior end of the body when the limb is extended at a right angle to the midline. retromargin The posterior margin of the cheliceral fang furrow. rhabdom The central zone of the retinula, which is the site of photoreception in the spider eye. rostrum The upper lip, lying between the chelicerae and the mouth and closing the preoral cavity in front. rugose Rough. scape A median unpaired projection of the epigynum, usually attached anteriorly and free to varying degrees posteriorly. sclerite A thickened, usually well-sclerotized plate in the body wall. sclerotized Hardened and darkened through tanning of the body-wall proteins. segment One of a series of divisions into which the body or an appendage is divided. seminal duct A tube that conducts semen to and from the reservoir within the genital bulb via the embolus. serrate Toothed. seta (pl., setae) An elongated outgrowth of the body wall secreted by a single cell and supplied with a nerve; setae form the normal covering of the spider’s body. setose Having many setae. signal thread The silk thread connecting the spiders’s retreat to the hub of the web. sinuous Undulating smoothly.

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spermatheca (pl., spermathecae) One of a pair of semen-storing organs in female spiders. sperm induction The process whereby mature male spiders deposit semen on a silk substrate and take it into the reservoir within the genital bulb. spigot One of the tubelike organs through which liquid silk from the silk glands is emitted to the outside. spine A fixed, usually pointed, outgrowth of the body wall. spinneret One of the paired appendages at the posterior end of the abdomen and bearing the spigots; the spinnerets are in three pairs: anterior, median, and posterior. spiral thread Thread placed spirally in the orb web as part of the auxiliary spiral or the sticky spiral. spur A short stout spine. stabilimentum A silk thread or threads usually forming a dense band, cross, circle, or spiral in the webs of some orb weavers. sternum The ventral wall of a body segment; term also used for the fused sterna of the cephalothorax. sticky spiral The silk thread forming the catching element of the completed orb web. submargin An area lying parallel to the margin of a sclerite or body region. subtegulum A ringlike sclerite in the wall of the basal haematodocha of the genital bulb. subterminal apophysis A small sclerite adjacent to the terminal apophysis of the genital bulb. swathing band A broad band of dense white silk used in the wrapping of prey. tapetum A carpet or sheath of cells behind the retina of the eye that reflects incoming light outward again, thus increasing the spider’s vision and causing the shining of the eyes in faint light. tarsus (pl., tarsi) The sixth segment of a leg or palpus from the base; in legs, subdivided into basitarsus and distitarsus. tegular crest A crest, or ridge, on the tegulum of some orb weavers. tegulum A sclerite, usually the largest, in the genital bulb. tension line A thread spun between the hub of the web and some nearby object such as a plant stem. terminal apophysis A variously shaped sclerite of the distal part of the genital bulb. tibia (pl., tibiae) The fifth segment from the base of a leg or palpus, forming a rigid piece with the patella. trachea One of the respiratory tubes within the body. tracheal spiracle A median opening posteriorly on the venter allowing respiratory gases to pass in or out of the tracheae.

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trap line Same as tension line. trichobothrium A fine erect sensory seta arising from a rimmed socket found on the legs of spiders and detecting air-borne vibrations. trochanter the second segment of a leg or palpus from the base. truncate Squared at the tip. tubercle A small, fixed, usually rounded prominence. venom gland The venom-secreting gland within the chelicera and sometimes extending into the cephalothorax; its duct opens on the tip of the fang. venter The undersurface of the body as a whole or of the abdomen or an appendage. ventral Pertaining to the venter. ventrally Toward the venter.

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References Alderweireldt, M., and R. De Keer. 1990. Field and laboratory observations on the life cycle of Pachygnatha degeeri Sundevall, 1830 and Pachygnatha clercki Sundevall, 1823 (Araneae, Tetragnathidae). Acta Zoologica Fennica, 190:35-39. Anderson, C.M., and E.K. Tillinghast. 1980. GABA and taurine derivatives on the adhesive spiral of the orb web of Argiope spiders, and their possible behavioural significance. Physiological Entomology, 5:101–106. Archer, A.F. 1940. The Argiopidae or orb-weaving spiders of Alabama. Geological Survey of Alabama, Alabama Museum of Natural History, Museum Paper No.14:1–77. Archer, A.F. 1951. Studies in the orbweaving spiders (Argiopidae). 2. American Museum Novitates No. 1502:1–34 Arthur, C. 1994. Hunt is on for money-spinning spider gene. New Scientist, 142:19. Audouin, V. 1826 [“1825”]. Explication sommaire des planches d'Arachnides de l'Égypte et de la Syrie, publiées par Jules-César Savigny, membre de l'Institut; offrant un exposé des caractères naturels des genres, avec la distinction des espèces. Pages 99–186 in Description de l'Égypte ou recueil des observations et des recherches qui ont été faites en Égypte pendant l'expédition de l'armée française, publiée par les ordres de sa Majesté l'Empereur Napoléon Le Grand. Histoire naturelle. Tome premier, partie 4. Banks, N. 1892. The spider fauna of the Upper Cayuga Lake basin. Proceedings of the Academy of Natural Sciences of Philadelphia, 1:11–81 + pl. I–V. Banks, N. 1894. Notes on Larinia and Cercidia. Entomological News, 5(1):8–9. Banks, N. 1896a. New North American spiders and mites. Transactions of the American Entomological Society, 23:57–77. Banks, N. 1896b. New Californian spiders. Journal of the New York Entomological Society, 4:88–91. Banks, N. 1898. Arachnida from Baja California and other parts of Mexico. Proceedings of the California Academy of Sciences, Third Series, Zoology, 1(7):205–309. Banks, N. 1901. Notes on some spiders of Walckenaer, Koch and others. Journal of the New York Entomological Society, 9:182–189. Banks, N. 1904. New genera and species of nearctic spiders. Journal of the New York Entomological Society, 12(2):109–119 + pl. V–VI. Banks, N. 1906. Descriptions of new American spiders. Proceedings of the Entomological Society of Washington, 7:94–100. 341

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Banks, N. 1907. A preliminary list of the Arachnida of Indiana, with keys to families and genera of spiders. Annual Report of the Geological Survey of Indiana, 31:715–747. Banks, N. 1909. Arachnida of Cuba. Estación central agronómica de Cuba, Second Report, Part II. Pages 150–174 + pl. XLV. Banks, N. 1910. Catalogue of Nearctic spiders. Bulletin of the United States National Museum, 72:1–80. Barrows, W.M. 1915. The reactions of an orb-weaving spider, Epeira sclopetarius Clerck, to rhythmic vibrations of its web. Biological Bulletin of the Marine Biological Laboratory, Woods Hole, Mass. 29:316–332. Barrows, W.M. 1919. The taxonomic position of Mysmena bulbifera (Glenognatha bulbifera) Banks, with some observations on its habits. Ohio Journal of Science, 19:210–212. Barth, F.G. 1982. Spiders and vibratory signals: sensory reception and behavioral significance. Pages 67–122 in P.N. Witt and J.S. Rovner, eds. Spider communication: Mechanisms and ecological significance. Princeton University Press, Princeton, N.J. Barth, F.G. 2002. A spider’s world, senses and behavior. Springer, New York, N.Y. Beard, J. 1992. Warding off bullets by a spider thread. New Scientist, 136:18. Becker, L. 1879. Diagnoses de nouvelles Aranéides américaines. Annales de la Société Entomologique de Belgique, 22:77–86 + pl. I–II. Beckwitt, R., and S. Arcidiacono. 1994. Sequence conservation in the C-terminal region of spider silk proteins (Spidroin) from Nephila clavipes (Tetragnathidae) and Araneus bicentenarius (Araneidae). Journal of Biological Chemistry, 269:6661–6663. Berman, J.D. and H.W. Levi. 1971. The orb weaver genus Neoscona in North America (Araneae: Araneidae). Bulletin of the Museum of Comparative Zoology, Harvard University, 141:465–500. Blackledge, T.A. 1998. Stabilimentum variation and foraging success in Argiope aurantia and Argiope trifasciata (Araneae : Araneidae). Journal of Zoology, London, 246:21–27. Blackwall, J. 1846. Notice of spiders captured by Professor Potter in Canada, with descriptions of such species as appear to be new to science. The Annals and Magazine of Natural History, (1)17:30–43, 76–82. Blagbrough, I.S., B.W. Bycroft, A.J. Mather, and P.N.R. Usherwood. 1989. Low molecular weight spider venom toxins isolated from Argiope and Araneus:

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Index Index to names of superfamiles, families, genera, and species (Page numbers of principal entries are in boldface; synonyms are in italic type) Acanthepeira 123, 124, 127, 128, 309 aculeata, Epeira 177 Aculepeira 2, 122, 125, 126, 129, 175, 315 alba, Epeira 193 alberta, Hypsosinga 287, 288, 289 alboventris, Araneus 242, 243 alboventris, Conepeira 242 alboventris, Epeira 242 alpina, Metepeira 324 ambitoria, Epeira 155 americana, Meta 116 americanus, Hyptiotes 36 americanus, Uloborus 43 Anapidae 13 anastera, Epeira 267 anastera, Eustala 267, 268 andrewsi, Araneus 211 angulata var. bicentenaria, Epeira 209 apotroga, Epeira 267 arabesca, Epeira 171 arabesca, Neoscona 171, 172 Araneidae 13, 120, 121 Araneoidea 13 Araneus 27, 122, 123, 124, 125, 126, 127, 128, 129, 198 Araniella 122, 124, 126, 128, 191 argentatum, Theridosoma 329 argenteolum, Theridosoma 329 Argiope 2, 27, 120, 122, 125, 153 argyraspides, Epeira 157 arkansa, Neoscona 173 arkansana, Eustala 269 atrica, Eucharia 298 atrica, Zilla 298 atrica, Zygiella 298, 299 attestor, Araneus 242 attestor, Epeira 242 aurantia, Argiope 30, 31, 155, 156 aurantia, Argyope 155 aureola, Epeira 233 aurelia, Argyope 157 autumnalis, Pachygnatha 89, 90, 91, 96, 97

avara, Argyope 157 baltimorensis, Epeira 213 banksi, Linyphia 282 banksi, Tetragnatha 81 benjamina, Neoscona 173 bicentenaria, Aranea 209 bicentenaria, Epeira 209 bicentenarius, Araneus 209, 210 bicolor, Linyphia 282 biologia, Pseudometa 300 boesenbergii, Zilla 300 borealis, Larinia 312, 313, 314 bovinum, Acrosoma 143 brevis, Pachygnatha 89, 90, 91, 102, 103, 104 bulbifera, Mysmena 48 californica, Zilla 300 campestris, Singa 275 canadensis, Epeira 162 canmorus, Araneus 247 carbonaria, Epeira 179 carbonarioides, Epeira 179 carbonarioides, Aculepeira 179, 180, 181 caudata, Epeira 164, 244 caudata, Tetragnatha 55, 56, 57, 59, 60, 61, 62 cavatica, Aranea 244 cavatica, Epeira 244 cavaticus, Araneus 244, 245, 246 cavatus, Hyptiotes 22, 25, 36, 37, 38 cepina, Epeira 271 cepina, Eustala 271, 272, 273 Cercidia 120, 122, 124, 126, 128, 261 charitonovi, Aranea 181 cinerea, Epeira 244 cingulata, Epeira 256 cingulatus, Araneus 256, 257, 258 clerckii, Pachygnatha 90, 91, 94, 95 comstocki, Micrathena 143 conica, Aranea 162 conica, Cyclosa 22, 162, 163

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convexa, Tetragnatha 76 cophinaria, Epeira 155 cornigera, Cyrtarachne 130 cornigera, Mastophora 130 cornuta, Nuctenea 185 cornutus, Araneus 185 cornutus, Larinioides 184, 185, 188 corticaria, Aranea 226 corticaria, Epeira 226 corticarius, Araneus 226, 227, 228 croaticus, Araneus 193 crucifera, Epeira 173, 317 crucifera, Neoscona 173, 174, 175 crumbi, Diplocephalus 48 cubana, Singa 282 cucurbitina, Araniella 196 culta, Cyclosa 164 curtisi, Metellina 108, 109, 113, 114, 115 curtisi, Pachygnatha 113 Cyatholipidae 13 Cyclosa 2, 122, 124, 126, 128, 160 dakota, Metepeira 324 darlingtoni, Aranea 219 dearmata, Tetragnatha 56, 57, 58, 60, 85, 86, 87 decipiens, Epeira 193 decolorata, Epeira 267 Deinopidae 13 Deinopoidea 13 denningi, Aranea 226 diadema, Aranea 216 diadematus, Araneus 2, 14, 120, 200, 203, 204, 216, 217 dispar, Zygiella 303, 304, 305 displicata, Aranea 193 displicata, Araniella 193, 194, 195 displicata, Epeira 193 displicata octopunctata, Araniella 193 displicatus, Araneus 193 distincta, Microneta 282 diversus, Uloborus 23 domiciliorum, Epeira 173 dorothea, Pachygnatha 89, 90, 91, 105, 106 dugesi, Cyrtarachne 309 dumetorum, Aranea 186

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dumetorum, Epeira 186 elongata, Tetragnatha 56, 58, 69, 83, 84 emertoni, Epeira 269 emertoni, Eustala 269, 270, 271 Enoplognatha 296 epeiroides, Theridiosoma 328 eugeni, Singa 277, 278, 279 eustala, Epeira 267 Eustala 123, 127, 128, 176, 264 extensa, Aranea 71 extensa, Tetragnatha 55, 57, 58, 69, 71, 72, 73 fastuosa, Aranea 157 flavipes, Epeira 157 floridana, Singa 254 foliata, Aranea 185 foliata, Epeira 185 foxi, Glenognatha 48, 49 foxi, Metepeira 316, 317, 321, 322 foxi, Mimognatha 48 foxi, Theridium 48 funebris, Cercidia 292 funebris, Hypsosinga 292, 293, 294 furcillata, Pachygnatha 89, 91, 100, 101, 102 Gea 122, 125, 150 gemma, Araneus 249, 250, 251 gemma, Epeira 246, 249 gemmoides, Araneus 246, 247, 248 gemmosum, Theridiosoma 2, 22, 329, 330, 331 gemmosum, Theridium 329 gemmus, Araneus 249 geniculata, Zosis 34 gertschi, Hyptiotes 36, 38, 39, 40 gibberosa, Epeira 134 gibberosa, Mangora 134, 135, 136 Glenognatha 46, 47 globosa, Epeira 213 glomosa, Epeira 41 glomosus, Uloborus 2, 23, 41, 42, 43 glyphica, Conepeira 259 godmani, Argiope 156 gosogana, Aranea 233 gracilis, Epeira 146 gracilis, Micrathena 28, 146, 147

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gracilis, Plectana 146 grallator, Tetragnatha 85 grandiosa, Metepeira 316, 317, 324, 325, 326 grandiosa alpina, Metepeira 324 grandiosa grandiosa, Metepeira 324 grandiosa palustris, Metepeira 322 groenlandica, Hypsosinga 285, 286, 287 groenlandica, Singa 285 groenlandicola, Araneus 230, 231, 232 groenlandicolus, Araneus 230 guatemalensis, Tetragnatha 55, 56, 58, 59, 81, 82 guttulata, Epeira 259 guttulatus, Araneus 259, 260, 261 harrodi, Tetragnatha 85 hentzi, Singa 290 hentzii, Epeira 173 hentzii, Neoscona 173 heptagon, Epeira 151 heptagon, Gea 151, 152 heptagon var. nigra, Gea 151 hortorum, Epeira 51 hutchinsoni, Mastophora 130, 131, 132 hyperboreus, Araneus 181 Hypsosinga 2, 123, 127, 280 Hyptiotes 2, 34, 35, 36 illinoiensis, Tetragnatha 74 illustrata, Epeira 267 incestifica, Epeira 226 index, Cyclosa 164 innominata, Conepeira 256 insularis, Epeira 221 intermedia, Tetragnatha 81 itemvarians, Araneus 284 ithaca, Epeira 186 iviei, Aranea 240 iviei, Araneus 240, 241 juniperi, Epeira 254 juniperi, Araneus 254, 255, 256 keyserlingi, Aranea 317 keyserlingi, Singa 275, 276, 277 kisatchia, Aranea 209 kuratai, Pachygnatha 105

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laboriosa, Tetragnatha 55, 56, 58, 69, 74, 75 labyrinthea, Epeira 272, 317 labyrinthea, Metepeira 316, 317, 318, 319 Larinia 123, 124, 127, 128, 176, 312 Larinioides 2, 122, 124, 126, 128, 182 laudativa, Tetragnatha 81 Leucauge 46, 50 limnocharis, Tetragnatha 76 Linyphiidae 13 listerii, Singa 237 llano, Conepeira 254 maculata, Epeira 139 maculata, Mangora 139, 140 maculata, Singa 289 mammeata, Phillyra 41 Mangora 2, 53, 121, 125, 133 manitoba, Tetragnatha 71 manitobae, Aranea 230 marianna, Tetragnatha 78 marilandica Conepeira 256 marmorea, Epeira 221 marmoreus, Araneus 31, 221, 222, 223 Mastophora 121, 125, 129 maulliana, Larinia 300 melania, Singa 282 menardii Meta 116, 118, 119 Meta 46, 47, 107, 116 Metellina 2, 46, 47, 107, 108 Metepeira 123, 124, 127, 129, 176, 315 Micrathena 120, 121, 125, 144 mimetoides, Metellina 108, 109, 110 minima, Neoscona 172 mitrata, Acrosoma 148 mitrata, Epeira 148 mitrata, Micrathena 148, 149, 150 modesta, Singa 290 montana, Neosconella 191 montereyensis, Araneus 251, 252, 253 montereyensis, Conarana 251 mumai, Conepeira 254 Mysmenidae 13 nanna, Cyclosa 164 nanella, Metepeira 320 nearctica, Zygiella 306, 307, 308 nebraskensis, Neoscona 173

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Neoscona 27, 122, 124, 126, 128, 166 Nephila 26 Nesticidae 13 nigra, Epeira 224 nigrior, Micrathena 146 nigripes, Singa 290 nobilis, Epeira 309 nordmanni, Aranea 219 nordmanni, Araneus 2, 219, 220 nordmanni, Epeira 219 Nuctenea 183 numa, Tetragnatha 74 obesa, Epeira 221 ocellatus, Araneus 186 Octonaba 34 opisthographa, Araniella 198 Orbiculariae 13 orotes, Singa 292 ovalis, Auchicybaeus 116 ovalis, Meta 116, 117, 118 ovigera, Aranea 189 ozarkensis, Conepeira 256 Pachygnatha 2, 31, 46, 47, 88, 89 packardi, Aculepeira 177 packardii, Aculepeira 177, 178, 179 packardii, Epeira 177 pallescens, Tetragnatha 55, 56, 58, 59, 64, 65, 66 pallida, Tetragnatha 64 pallidula, Eugnatha 66 palomara, Metepeira 324 palustris, Metepeira 316, 317, 322, 323 parvula, Epeira 271 patagiata, Nuctenea 186 patagiatus, Araneus 186 patagiatus, Larinioides 186, 187, 188 peckhamii, Epeira 113 pegnia, Epeira 213 pegnia, Araneus 213, 214, 215 personata, Argiope 156 Pimoidae 13 pinea, Tetragnatha 78 pinicola, Tetragnatha 78 pirus, Araneus 249 placida, Epeira 136 placida, Mangora 136, 137, 138 plana, Argiope 158

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platycephala, Brachygea 158 plumipes, Uloborus 41 pradhani, Argiope 158 praecincta, Ebaea 151 praedicta, Gea 151 praetrepida, Epeira 136 pratensis, Araneus 237, 238, 239 pratensis, Epeira 169 pratensis, Neoscona 169, 170 pratensis, Singa 237 praticola, Araneus 237 prominens, Cercida 262, 263, 264 prominens, Epeira 262 proxima, Araniella 196, 197 proxima, Epeira 196 pseudomelaena, Aranea 219 pygmaea, Hypsosinga 282, 283, 284 pygmaea, Singa 282 pygmaea, Theridion 282 raji, Aranea 221 raji, Epeira 221 reaumuri var. groenlandicola, Aranea 230 reduviana, Plectana 146 reptilis, Epeira 237 reticulata, Aranea 111 reticulata, Meta 111 riparia, Epeira 155 riparia var. multioncha, Argiope 155 riparia, Phyllyra 41 rubens, Epeira 289 rubens, Hypsosinga 289, 290, 291 rugosa, Acrosoma 146 rugosa, Epeira 146 rusticana, Tetragnatha 71 sachimau, Aranea 240 saeva, Epeira 224 saevus, Araneus 224, 225 sagittata emertoni, Micrathena 143 sagittata, Micrathena 143, 144, 145 sagittata, Plectana 143 sanguinalis, Epeira 259 sarasota, Conepeira 254 schefferi, Singa 292 sclopetaria, Nuctenea 189 sclopetarius, Araneus 189 sclopetarius, Larinioides 2, 26, 189, 190

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segmentata, Metellina 108, 111, 112 segmentatus, Araneus 111 seneca, Tetragnatha 81 septentrionalis, Araneus 177 sericatus, Araneus 189 sewardi, Pachygnatha 94 sexpunctata, Epeira 193 shoshone, Tetragnatha 55, 56, 58, 59, 70, 71 sinensis, Octonaba 34 Singa 123, 124, 127, 128, 274 singaeformis, Araneus 292 singularis, Epeira 171 solersioides, Epeira 214 solitaria, Aranea 224 spatulata, Epeira 267 spinea, Acrosoma 143 spinea, Epeira 143 stellata, Epeira 29 stellata, Acanthepeira 309, 310, 311 straminea, Tetragnatha 55, 56, 58, 59, 67, 68 strix, Epeira 185 sutrix, Epeira 155 sylvatica, Epeira 219, 224 Symphytognathidae 13 Synotaxidae 13 Tetragnatha 31, 46, 53, 54, 57 Tetragnathidae 13, 45, 46 thaddeus, Epeira 211 thaddeus, Araneus 211, 212, 213 Theridiidae 13 Theridiosoma 329 Theridiosomatidae 13, 328 triangularis, Linyphia 13 triaranea, Epeira 213 trifasciata, Aranea 157 trifasciata, Argiope 28, 30, 157, 158, 159 triflex, Epeira 267 trifolium, Epeira 233 trifolium, Araneus 233, 234 trinota, Epeira 267 tristriata, Pachygnatha 89, 90, 91, 98, 99, 102 trivittata, Epeira 171 truncata, Singa 290 turbinata, Epeira 164

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turbinata, Cyclosa 164, 165, 166 tusigia, Aranea 221 tusus, Araneus 290 tytera, Epeira 213 Uloboridae 13, 33, 34 Uloborus 34, 40 undata, Epeira 189 vanbruysselii, Singa 164 varians, Araneus 282 variabilis, Hypsosinga 282, 284 variabilis, Singa 282 vegae, Araneus 181 venusta, Epeira 51 venusta, Leucauge 51, 52 verae, Aculepeira 177 vermiformis, Tetragnatha 55, 56, 59, 62, 63 versicolor, Tetragnatha 55, 57, 58, 60, 76, 77 vicaria, Epeira 185 viridis, Tetragnatha 55, 57, 58, 60, 78, 79, 80 washingtoni, Araneus 228, 229, 230 webii, Epeira 157 xanthostoma, Pachygnatha 89, 90, 91, 92, 93 x-notata, Zygiella 2, 31, 300, 301, 302 x-notatus, Araneus 300 yukon, Araneus 235, 236, 237 Zosis 34 Zygiella 120, 123, 125, 127, 129, 294

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