Cofrin Center for Biodiversity

spider: G. Fewless

The Spider Species of the Great Lakes States

Petra Sierwald
Zoology Department, The Field Museum, Chicago, Illinois USA

Michael Draney
Department of Natural and Applied Sciences and Cofrin Center for Biodiversity, University of Wisconsin-Green Bay, Green Bay, Wisconsin USA

Thomas Prentice
Department of Entomology, University of California, Riverside, California USA

Critical analysis of existing spider species lists for Wisconsin, Michigan, Ohio, Indiana and Illinois reveal 899 species recorded from the five-state region (284 genera, 40 families). Illinois currently has the highest recorded total with 622 species, followed by 571 from Ohio, 563 from Michigan, 477 from Wisconsin, and 385 from Indiana. All non-native, non-established, or otherwise questionable species records were scrutinized and their status is discussed. The most speciose families in the region are Linyphiidae (almost 24% of species), Salticidae (10.3%), Theridiidae (8.9%), Lycosidae (8.8%), and Araneidae (7.7%). The configuration of the five states, as well as the topography and glacial history of the region enabled us to generate predictions of over 400 new state species occurrences based on their known presence within each of the five states, and to produce higher minimum estimates of the actual fauna in each state. Richness among states is analyzed and found to be primarily dependent on varying degrees of sampling effort. We feel this work shows that much remains to be learned about the fauna of the Great Lakes region, and we hope this encourages basic faunistic research.

We are creating a searchable online database which allows access to all published data, returning currently valid taxa starting from any names previously published from this region. The database will be:

Centralized, critical compilation of known spider records from the five state region.
Searchable by taxon or geographic area, and will return currently valid names starting with any spider names ever used in regional studies.
Database will be updated over time as new research is published.

Search the Database

(Please note that the database is still under construction and will be updated in January 2006)