Degree Name

Master of Science (MS)

Semester of Degree Completion


Thesis Director

Bill T. Ridgeway


This study was conducted to determine what ectoparasitic organisms are found on the pairie pocket gophers, Geomys burasrius, occurring in an isolated population in northeastern Illinois. The study area was a five hectare grassland community composed predominately of sandy soil, located in northeastern Iriquois Co., two miles north and three miles east of Beaverville, IL.

A total of 19 pocket gophers were captured from October 2 to November 17, 1983. Blood was collected and smears were made in the field. Hosts were examined for ectoparasites in the laboratory. Six hundred and nine ectoparasitic organisms were isolated representing a mean of 32.1 parasites per host.

Mites were the most abundant ectoparasite, accounting for 41.4% of the total removal. Two genera were isolated. Haemolaelaps spp. were most numerous occurring on 17 hosts, while the genus Hirstionyssus spp. was less numerous, occurring on 4 hosts. An average of 13.3 mites was found per host.

Lice were also numerous, representing 40.7% of the ectoparasite recovery. Geomydoecus illinoensis was the only species collected. It was isolated from 15 to 19 host animals. An average of 13.1 lice per host was found throughout.

A less abundant ectoparasite was the flea Foxella ignota, accounting for only 5.7% of the total. It was found on 16 host animals, supporting an average of 5.7 per individual.

No ticks were found. Examination of the blood smears and other blood samples yielded no evidence of microfilarial or protozoan parasites.

Parasite distribution varied with sex of the host. Males supported more parasites than the females. Furthermore, lice were associated most often with the males, while mites were most often found on female host. In general, most ectoparasites were concentrated around the head and neck of the host. Other researchers have demonstrated much larger parasitic yields in similar hosts than was found in this study. Variables such as climate, host species, season, and recovery technique can account for this difference. It was also observed that generally one species of ectoparasite was found per host.