Lice collected from the prairie vole were all of one species,
_Hoplopleura acanthopus_ (Burmeister). Of 59 voles examined for the
presence of lice, 33 were found to be parasitized; the 59 voles had an
average of 3.4 lice each. Other mice which used the same runways as the
prairie vole had their own species of Anoplura. The cotton rat was host
to _Hoplopleura hirsuta_ Ferris, and the two species of _Peromyscus_
were parasitized by _Hoplopleura hesperomydis_ (Osborn).
The writer collected _Hoplopleura acanthopus_ from _Microtus
californicus_ at Calaveras Dam, Alameda County, California, and from _M.
pennsylvanicus_ at Ithaca, Tompkins County, New York. Elton, Ford,
Baker, and Gardner (1931) recorded this same species from _M. argestis_
in England.
Lice on the prairie vole are the same species as those found on other
species of _Microtus_ in other areas, but since Anoplura of the prairie
vole do not parasitize the cotton rat, the white-footed mouse, and the
deer mouse, this host specificity of lice makes it unlikely that lice
would carry blood parasites from the prairie vole to any of the latter
named rodents.