Western Michigan University ScholarWorks at WMU Master's Theses Graduate College 12-1976 Studies of Michigan Lycosidae Robert John Wolff Follow this and additional works at: https://scholarworks.wmich.edu/masters_theses Part of the Zoology Commons Recommended Citation Wolff, Robert John, "Studies of Michigan Lycosidae" (1976). Master's Theses. 2298. https://scholarworks.wmich.edu/masters_theses/2298 This Masters Thesis-Open Access is brought to you for free and open access by the Graduate College at ScholarWorks at WMU. It has been accepted for inclusion in Master's Theses by an authorized administrator of ScholarWorks at WMU. For more information, please contact [email protected]. STUDIES OF MICHIGAN LYCOSIDAE by Robert John Wolff A Thesis Submitted to the Faculty of the Graduate College in partial fulfillment of the Degree of Master of Arts Western Michigan University Kalamazoo, Michigan December 1976 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNOWLEDGEMENTS Thanks go to my committee, Doctors Joseph G. Engemann, Clarence J. Goodnight and William B. Harrison III for their guidance and advice. Special thanks go to Dr. Allen R. Brady, Hope College, for loan of specimens and technical help, and Norm Elliott for assistance in many ways. Drs. Roland Fischer, Michigan State University and Andrew Penniman, Ohio State University added to this study hy the loan of specimens. The Kalamazoo Nature Center and Michigan Audubon Society graciously allowed collecting on their land. A grant from the Graduate College at Western Michigan Uni­ versity, which helped to defray travel costs, is greatly appreciated. For all of the above help I am grateful, but I would not have succeeded quite as well without the encouragement of my wife Marcia. Robert John Wolff Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 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University Microfilms International 300 North Zeeb Road Ann Arbor, Michigan 48106 USA St. John's Road, Tyler's Green High Wycombe, Bucks, England HP10 8HR Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. I I MASTERS THESIS 13-9846 WOLFF, Robert John STUDIES OF MICHIGAN LYCOSIDAE. Western Michigan University, M.A., 1976 Zoology Xerox University Microfilms,Ann Arbor, Michigan 48106 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE OF CONTENTS SECTION PAGE I INTRODUCTION................................ 1 II MICHIGAN FAUNA ............................. 5 Arctosa ................................. 6 Geolycosa.. .............................. 9 L y cosa................................... 13 Pardo s a ................................. 16 Pirata ................................. 34 Schizocosa ............................. 34 Tarentula .................. 34 Trabea ........................... 35 Trochosa................................. 35 III HABITAT STUDIES ........................... 42 Old Fields............................... 43 Population Estimate ..................... 46 IV DISCUSSION................................. 48 BIBLIOGRAPHY .............................. 51 iii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. INTRODUCTION Wolf spiders are wandering, active spiders of the family Lycosidae. They are among the most important and abundant predators of the soil surface and leaf litter communities. Despite the dominance of lycosids there are still many aspects of the taxonomy, ecology and biology of these spiders which are unknown. This study is an attempt to take a broad look at many of these aspects and to be­ come familiar with these interesting spiders. An excellent description of spider natural history in the book 'American Spiders' (Gertsch, 19^-9) should be read by everyone interested in spiders. More recently, Turnbull (1973) reviewed the ecology of true spiders, and discusses some aspects of lycosid ecology. Wolf spiders generally do not build webs, but wander in search of prey or simply wait for insect prey to wander into them. Knost and Rovner (1975) demonstrated that wolf spiders will scavenge. The wandering habit of some lycosids makes pit fall trapping an effective, but biased, capture device. Head lights are useful for spotting wolf spiders, which are night active, because of the reflective properties of lycosid eyes (Wallace, 1937)- Life history data may be easily obtained for lycosids because the females carry their egg sac at­ tached to the spinnerets, and the young after hatching from the egg sac will hold on to special abdominal hairs (Rovner, 1 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 2 Higashi and Foelix, 1973)• Soon after hatching, the young of many species leave the mother, climb to a high spot, and spin out silk until wind currents pick them up and transport them. This is termed ballooning and may account for the wide distribution of many species, though its efficiency has been questioned (Platnick, 1976). Lycosids are often the dominant spiders on the ground surface. In Florida, wolf spiders accounted for 64$, 54$, 53$ and 18$ of the ground spiders in four different habitats (Muma, 1973)* Uetz (1976) found lycosids dominant in three of four sites along a stream in Illinois, in­ cluding over 90$ in two of the sites. Distribution in habitats is not well known for many species of spiders. Lowrie (1948) shows the distribution of spiders through the successional stages in the southern Lake Michigan area. Barnes (1953) gives the distribution of spiders in several plant communities along the Atlantic Ocean in North Carolina. In the Netherlands, Van der Aart (1973) analyzed wolf spider distribution and its correla­ tion to vegetation structure. He found that the spiders are distributed in relation to the vegetation. Wolf spiders and their systematic position are dis­ cussed by Kaston (1948). The family Lycosidae belongs to the superfamily Lycosoidea, which lack a cribellum (ecribellate), are three clawed (trionychous), have com­ plicated genitalia (entelegyne) and have one or two rows Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. of tarsal trichobothria. This superfamily also includes the families Agelenidae, Pisauridae and Oxyopidae, or the funnel web weavers, fisher spiders and the lynx spiders respectively. Lycosids are recognized by the eight un­ equal eyes forming three rows and the lorum of the pedicel having an anterior sclerite fitting into a notch in the posterior sclerite. The order is the Araneae, which in­ cludes all spiders, and is in the class Arachnida. The Michigan spider fauna is not very well known. Chickering (1932, 1933, 193^, and 1935) and Chickering and Bacorn (1933) listed species occurring in Michigan but the identifications are doubtful due to taxonomic difficulties. Drew (1967) contains a list of the spiders of Beaver Island, Charlevoix County and includes habitats of these species. Levi and Field (195^) and Levi, Levi and Kaspar (1958) con­ tain Wisconsin records. Kaston (1955) has some Illinois records. The Connecticut spider fauna is given in Kaston (19^8) with descriptions and habitat data, and is the best identification guide to eastern U. S. spiders. A key to lycosid genera is given by Kaston (1972) and Leech (1969), but both must be used with care. For example, due to variation in the number of cheliceral teeth (Gertsch, 193^), some specimens of Trochosa pratensis will key out to the genus Tarentula.