Brigham Young University Science Bulletin, Biological Series


Mites, Kangaroo rats, Radiation, Nevada Test Site (Nevada)


A systematic study of parasitic mites on kangaroo rats of two species at the Nevada Test Site was conducted from August 1959 to December 1961. The intent was to determine the kinds, numbers, seasonal occurrences and ecological relationships of mites in nuclear disturbed and contiguous undisturbed areas. A total of 1,256 rats from nine plant communities was examined.

The 6,208 mites collected represented 16 species including four undescribed. Fourteen were found on both kinds of rats. Considerably more rats were infested with chiggers than with mesostigmatids. Each species of mite occurred alone on its host at least 20% of the time, and one species was found alone as much as 67% of the time. Chiggers of two species occurred predominantly on the ears of their hosts, whereas mites of another species were found principally on the underparts of the hind legs. Although most mite species were found in all plant communities, they occurred in abundance in only one or two. However, two species were abundant in several communities. Seasonal peaks in numbers of mites occurred during the three periods of February–March, July, and October–November. Forty percent fewer rats in the nuclear disturbed areas were infested than in undisturbed areas, and only one-third as many mites were found on rats in the disturbed as in the undisturbed areas.