Relationships of the White-Footed Mouse, Peromyscus Leucopus, and its Associated Fleas (Siphonaptera) in Southwestern Wisconsin1

Nine species of adult fleas were collected from cotton nests formed by Peromyscus leucopus in nestboxes in south-western Wisconsin. Epitedia wenmanni (Roths.) and Orchopeas leucopus (Baker) were the predominant species found, with the latter panseasonal in occurrence and the former rare in nests and on mice during the summer. Monopsyllus wagneri (Jordan) was rare in nests and on mice in winter but present in spring and summer. Peromyscopsylla scotti Fox was collected only fall, while Ctenophthalmus pseudagyrtes Baker occurred sporadically throughout the year. Four of the species collected are primarily parasites of other mammals. Numbers of the 2 predominant species increased significantly with increased mouse nesting activity. Flea sex ratios favored females or were approximately equal. No differences were detected between flea infestations in nests of female and male mice or in infestations in nests exposed to multiple use by lactating and pregnant females and/or juveniles when compared with nests exposed to multiple use by adults.