The Geomydoecus oregonus complex (Mallophaga: Trichodectidae) of the Western United States pocket gophers (Rodentia: Geomyidae)

Four species of the Geomydoecus oregonus complex are described and illustrated: G. oregonus Price and Emerson from Thomomys bulbivorus (Richardson); G. idahoensis Price and Emerson from the seven recognized subspecies of T. townsendii (Bachman); G. shastensis new species from 12 subspecies of T. bottae (Eydoux and Gervais) (type-host: T. b. leucodon Merriam); and G. hueyi new species from 9 subspecies of T. bottae (type-host: T. b. pallescens Rhoads). Distinctions between these taxa are shown using qualitative and quantitative characters and principal components analysis of quantitative characters. A discriminant function is provided for the separation of females of G. hueyi and G. shastensis. Keys are given for the identification of these four taxa.