The polytene chromosomes of the cells of the salivary glands of the larvae of Ch. plumosus L. 1758, Ch. entis Shobanov 1989, Ch. borokensis Kerkis et al. 1988 and Ch. curabilis Beljanina et al. 1990 from 20 reservoirs of six natural-territorial complexes of the Ural region were studied. On the basis of a cytotaxonomic study, it was established that natural complexes diff er from each other in the species composition of the “plumosus” group, the ratio (in %) between species and, certain parameters of cytogenetic variability of Ch. plumosus, Ch. entis and Ch. borokensis.
