Distributional Status and Natural History Observations of the Genus Argyrodes (Araneae: Theridiidae) in Kansas

Abstract

Members of the genus Argyrodes Simon (Theridiidae) are small, cryptic spiders that usually occur in the webs of other spiders. Although most species in the genus are tropical, 15 occur within the continental United States (Exline and Levi, 1962). The western or northwestern range limits of four species extend into eastern Kansas. The occurrence of the genus Argyrodes in Kansas was reported first in a checklist of spiders of the University of Kansas Kansas Ecological Reserves, in Douglas and Jefferson counties (Guarisco and Fitch 1995). Careful examination of the funnelwebs produced by members of the genus Agelenopsis (Agelenidae) revealed the presence of both Argyrodes trigonum (Hentz) and A. cancellatus (Hentz). Further field work led to the discovery of Argyrodes elevatus Taczanowski and A. pluto Banks in the southeastern part of the state. The currently known distributions of these four species in Kansas are: A. trigonum: Cherokee, Douglas, Jefferson, Labette, Montgomery A. cancellatus: Bourbon, Chautauqua, Cherokee, Crawford, Douglas, Jefferson, Labette, Montgomery, Neosho, Osage A. elevatus: Bourbon, Cherokee, Douglas, Labette, Montgomery, Woodson A. pluto: Cherokee, Labette Members of the genus Argyrodes may be difficult to locate because of their cryptic coloration, form, and behavior. Field and laboratory studies have uncovered fascinating aspects of their biology. Although occasionally building their own webs, these spiders routinely invade and reside in the webs of other spiders, where they function as commensals, competitors, kleptoparasites, scavengers, and predators (Vollrath, 1987).