Fleas (Siphonaptera) of cotton mice on a Georgia barrier island: a depauperate fauna.

From February 1993 through October 1994, 382 cotton mice Peromyscus gossypinus were live-trapped and examined for fleas on St. Catherines Island, Liberty County, Georgia. Orchopeas leucopus was the only species of flea collected, with an overall prevalence of 27% and a mean intensity of 3.8. This flea was more abundant on cotton mice during the cooler months, with peak infestation indices recorded in March 1993 and in January 1994. Five species of fleas (Polygenis gwyni, Stenoponia americana, Ctenophthalmus pseudagyrtes, Peromyscopsylla scotti, and O. leucopus) were collected from 29 cotton mice live-trapped in adjacent mainland localities during the same period. The depauperate flea fauna of cotton mice on St. Catherines Island suggests that either the original colonizing cotton mice were infested by only 1 species of flea (O. leucopus) and that no subsequent invasions of cotton mouse fleas have occurred, or that other cotton mouse fleas cannot establish on the island.