[Parasite-host relationship of flies and small mammals in the Omsk region]

A generalized analysis of data on a flea fauna, range of their hosts in various natural zones, and features of parasite-host relationships between fleas and small mammals obtained in the Omsk province during long term researches in 1963-1997 is given. 35 flea species are recorded. The most mass species both on animals and in their nest is Ctenophthalmus assimilis; the numerous species are Amalareus penicilliger, Megabothros rectangulatus, M. walkeri, Peromyscopsylla silvatica, Ctenophthalmus unciatus, Palaropsylla sorecis, Doratopsilla birulai, Neopsylla pleskei, Hystrichopsylla talpae; the usual species--Ceratopsyllus garei, M. calcarifer, M. turbidus, Frontopsylla elata, Amphipsylla sibirica, A. kuznetzowi, Peromyscopsylla dasycnema, Radinopsylla integella, Catalagia dacenkoi. Other species are less numerous or infrequent. The general infection rate of the flea populations on rodents and insectivores makes 30.4%. For certain species it reaches 65.1% (on red-backed vole Cletrionomys rutilus), for regular groups--86.9% (on shrews of the genus Sorex). The greatest variety of the flea populations is observed on Microtus arvalis, the least one--on Sorex caecutiens and S. daphaenodon. In the nests of small mammals the variety of fleas is significantly lower. Based on the index of flea species relative "loyalty" to small mammals and their nest we have recognized 6 groups of fleas.