Many of the small mammals examined in this study had mites, some of
which were collected and identified. Mites were collected from other
species of voles in several localities in the United States and in one
locality in Canada; as voles in widely separated regions are sometimes
hosts to the same species of mites, these records will be presented
here.
The frequency of some kinds of mites in the identified material suggests
that they are more abundant than other kinds. The occurrence of mites on
small mammals from Lawrence, Kansas, is presented in table 7.
The following comments can be made concerning the specificity and
geographic ranges of several species of mites:
_Liponyssus occidentalis_ Ewing was found only on _Cryptotis parva_.
_Eulaelaps stabularis_ (Koch) was one of the more common kinds found on
the prairie vole. This mite is rather large (about 1 mm. long) and is
frequently (with the following species) seen running through the pelage
of its host. In addition to the records for this species in table 1, it
was found to be a common parasite on _Pitymys pinetorum_ at Point Abino,
Welland County, Ontario. Elton, Ford, Baker and Gardner (1931) found
this same mite on _Apodemus sylvaticus_ and _Clethrionomys glareolus_ in
England.
_Atricholaelaps glasgowi_, like the preceding species, was one of the
commoner mites on the prairie vole. It was found also on _Pitymys
pinetorum_ at Point Abino, Welland County, Ontario; on _Microtus
pennsylvanicus_ at Ithaca, Tompkins County, New York; and on _M.
californicus_ at Calaveras Dam, Alameda County, California.
_Atricholaelaps sigmodoni_ occurred only on the cotton rat.
_Laelaps kochi_ was less commonly found than _Eulaelaps stabularis_ and
_Atricholaelaps glasgowi_. In Kansas the prairie vole and the cotton rat
were hosts to _Laelaps kochi_, and it occurred on _Microtus
pennsylvanicus_ at Ithaca, New York, and on _M. californicus_ at
Berkeley, California.
Trombiculidae are commonly known by their larvae which are called
chiggers or harvest mites. The white-footed mouse, the cotton rat, and
the prairie vole were parasitized at Lawrence. In the winter these mites
live in the ears of these small mammals, but in the summer they were
found both in the ears and on the rump. Those obtained in winter were
_Ascoschoengastia brevipes_ (Ewing); other species may be involved.
Listrophoridae was represented on the prairie vole by a species of
_Myocoptes_ and a species of _Listrophorus_. These mites cling to the
hairs of their host, and do not occur on the skin of the voles.
No evidence was seen that mites had any ill effect on the health of
their hosts. No voles had scabs on the skin; and the ears were not
swollen and disfigured as they sometimes are by chiggers. Although the
identity of a specimen of mite could not be determined until it was
mounted, a person could tell whether or not it was one of the larger,
very active Laelaptidae, one of the hair-clinging Listrophoridae, or one
of the tiny, orange Trombiculidae.
On July 12, 1946, three prairie voles were examined to determine the
number of mites they supported. The voles were freshly caught, no one of
them having been dead for more than five minutes before they were
examined. These three voles had an average of 25 Laelaptidae, 22
Listrophoridae, and 53 Trombiculidae.
Six species of mites (Ixodoidea excepted) were found on the prairie
vole. Four of these were collected also from other small mammals living
in the same habitat as this vole. Two species of mites were found to
occur on voles in New York, Kansas, and California.