A review of the Geomydoecus tolucae complex (Mallophaga: Trichodectidae) from Thomomys (Rodentia: Geomyidae), based on qualitative and quantitative characters

Geomydoecus tolucae is redescribed and illustrated; its known host range is 5 subspecies of Thomomys umbrinus from the Mexican states of Puebla, Veracruz, and Mexico. Four new species and subspecies of Geomydoecus are described from Arizona (USA) and Mexico: G. fulvi from T. bottae fulvus from Arizona; G. chihuahuae chihuahuae from 4 subspecies of T. umbrinus and T. bottae from Chihuahua and Arizona (type-host: T. u. mudrensis); G. chihuahuae emersoni from T. u. chihuahuae from Durango and southern Chihuahua; and G. pattoni from T. u. rhihuahuae from Durango. Distinctions between these taxa are shown using qualitative and quantitative characters and principal components analysis of quantitative characters. Discriminant functions for 2 or 3 characters are provided in instances where they are shown to offer enhanced differentiation over single characters. Keys are given to identify these 5 taxa.