[The karyotypic characteristics and chromosome polymorphism of three species of blood-feeding flies (Simuliidae, Diptera) inhabiting the Kola Peninsula and the Baikal Region].

Karyotypes of three species of black flies inhabiting the Kola Peninsula and the Baikal Region--Schoenbaueria pusilla, Gnus rostratum and G. decimatum--have been first described. The diploid number of these species is 2n = 6. The main identification signs of all chromosomes of the set were revealed and a high level of polymorphism in heterozygote inversions was found out. The detected heterozygote inversions are irregulary located in chromosomes, which is interpreted as an effective mechanism of populations highly adapted to different ecological conditions.