A review of the flea genus Rothschild, 1915 (Siphonaptera, Ctenophthalmidae, Neopsyllinae, Phalacropsyllini) with new host and distributional records.

A redescription of the genus Rothschild is provided. Six species are recognized: Wagner, Tipton and Mendez, Eads and Campos, Barrera and Traub, Lewis and Maser, and Rothschild. is designated herein as a junior synonym of . The distribution of is more extensive than previously thought, extending from Arizona through southern Colorado, into New Mexico, Texas, and northern Mexico (State of Nuevo León). It is the least host-specific of all species of , occurring on 13 different host species including cricetid, heteromyid, murid, and sciurid rodents and several carnivores, although it most commonly occurs on Hartley. The range of is expanded from eastern Oregon to southeastern Idaho. Numerous records are documented for the most common and ubiquitous species, , which is found in British Columbia, central to northern California, Idaho, Montana, Colorado, Nevada, Utah, Wyoming, Arizona, and New Mexico. Ord is the principal host of . is a winter flea west of the Rocky Mountains, but it has been reported in warmer months of the year on the eastern slopes of the Rocky Mountains in Larimer County, Colorado. A distribution map and key are provided for all species in the genus .