Arthropod and helminth parasites from the Plains Pocket Gopher, Geomys bursarius bursarius from the hosts' northern boundary range in Minnesota.

As part of a continuing and more general study of the diversity of parasites from subterranean mammals in central North America, individuals of the Plains Pocket Gopher, Geomys bursarius bursarius, were collected from 7 localities in northwestern Minnesota from September 1991 through October 1996. Arthropods collected included the fleas, Opisocrostis bruneri (4 of 124, 3.2%), Foxella ignota ignota (85 of 124, 68.5%); the chewing louse, Geomydoecus geomydis geomydis from 98 of 124 (79%), and larvae of the tick, Dermacentor variabilis (1 of 124, 0.8%). Nematodes found included Physaloptera limbata (2 of 118 gophers, 1.7%), Capillaria americana (4 of 118, 3.4%), and Ransomus rodentorum (31 of 118, 26.3%). Cestodes recovered included Anoplocephaloides infrequens (12 of 136 gophers, 8.8%), Anoplocephaloides variabilis (19 of 136, 14%), Andrya macrocephala (20 of 136, 14.7%), and Hymenolepis weldensis from 12 of 136, 8.8%. The acanthocephalan, Moniliformis clarki was found in 1 of 118 gophers (0.8%). No parasites were found in the cheek pouches, thoracic, or peritoneal cavities.

Comparison of Montana and Alaska isolates of Echinococcus multilocularis in gerbils with observations on the cyst growth, hook characteristics, and host response.

To assess its biological distinctness, an isolate of Echinococcus multilocularis from Montana was compared with an isolate from Alaska in gerbils (Meriones unguiculatus) by means of intraperitoneal inoculations with protoscoleces. The cysts formed by the Montana isolate were entire, hyaline, and translucent, whereas those produced by the Alaska isolate were granular, yellowish, and opaque. Vesicles of the Montana isolate were larger, produced protoscoleces more slowly but in greater numbers, and required a longer period to develop surfacial germ cell protrusions, which were of smaller size. Also delayed was invasion of the laminate layer by granulocytes and macrophages, and a longer time was required for the appearance of pulmonary metastases. The 2 isolates differed also in characteristics of rostellar hooks, those from the Montana isolate being fewer and larger, often with accessory hooks.