A Biogeographic Review of the Spider Genus Agelenopis (Araneae Agelenidae)

This study is a review of the biogeography of the North American spider genus Agelenopsis (Giebel) (Araneae: Agelenidae). Previous theoretical and empirical work provides support for the hypothesis that many North American taxa have been subject to disjunction and divergence due to the effects of Late Pleistocene glacial/interglacial cycles. A summary of the current knowledge of the biology and ecology of the 13 Agelenopsis species is developed and new distribution maps for each species are generated from published collections. A reconstructed phylogeny for the genus is created based on the adult sexual morphology of the species. A detailed hypothesis for the historical biogeography of the genus is developed combining information from the late Pleistocene history of North America, the reconstructed phylogeny and the current distributions of the species. It is concluded that the available information strongly supports the hypothesis that Late Pleistocene glacial/interglacial cycles were the driving force behind the origin and modern distribution of Agelenopsis species.