Protozoan, helminth and arthropod parasites of the gray squirrel in southwestern Virginia
Parker, James C.
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A comprehensive. qualitative and quantitative survey of parasites of 176 gray squirrels. Sciurus carolinensis pennsylvanicus, Ord. 1815, was conducted from September, 1966, to July, 1969, in southwestern Virginia. Most of the hosts came from Montgomery County, some being taken also from Giles and Craig counties. Of that total, 167 were examined for coccidia and intestinal flagellates; 84 were examined for blood parasites; 175 were examined for helminths and 106 for ectoparasitlc arthropods. The incidence of coccidiosis was 91% in which five species were described and identified with the genus, Eimerla. The sporozoan, Hepatozoon griseiscuri Clark. 1958, occurred In the blood as evidenced by a 58% incidence in stained blood smears and 79% in blood concentrates. Excysted gametes of this species were kept in vitro for four days without any apparent union or multiplication. The cysts of the flagellate, Giardi. sp., are reported for the first time in this host and occurred in 5% of those examined. Gray squirrels, hamsters, white mice, and a chipmunk were successfully infected with cysts obtained from a naturally infected squirrel. ln vitro cultivation of the trophozoites was partially successful. Cultures were maintained up to 21 days. In examinations for helminths, 3l of the hosts harbored adult cestodes of which two species were identified and 62% harbored nematodes of which 12 species were identified. From habitats designated "town, woodlot, forest fringes and remote forest," the highest incidence of nematode infestation occurred In the forest fringes sample. Nematodes were generally more prevalent among male squirrels than females and the average high incidence occurred during the spring. Numbers of worms per infection were generally higher in summer. The most common species were Citellinewa bifurcatum Hall, 1916. (45%), Strongyloides robustus Chandler, 1942, (28%), and Bohmiella wilsoni Lucker, 1943, (14%). The arthropod survey indicated 97% of the hosts were infested.Four species of lIce, two flies, one flea, one tick and six mites were reoovered. The greatest percentages of hosts infested, based on individual parasite species, were generally those collected during winter. The most common arthropods were Neohaematopinus sciuri Janoke, 1932, (81%). Orchopeas howardii (Baker, 1895), (74%) and Enderleinellus longiceps Kellogg and Ferris, 1915, (67%). Twenty-four adult squirrels (12 male. 12 female) were examined for total ectoparasites using a hair dissolving technique. Also the surface areas of those squirrels were calculated by body regions so that parasite densities could be determined. The results showed the highest densities generally occurred on the back, followed by legs, underparts, bead and tail. Parasite densities were generally greater on males. The preferences by the various species for certain body regions were determined from density data. A number of incidental arthropods were also encountered in these studies. Modified nest-funnels were constructed and placed in campus woodlots and monitored for a year. A list of the arthropod species occurring in these nests is given. Several new host records, a number of distributional records and one new species were evidenced in this study.
- Doctoral Dissertations