Based upon the detailed chromosome map of polytene chromosomes of the eurybiont species Endochironomus
albipennis Meigen, 1830, the localization of the centromere regions using a C-banding technique is defined. Chromosomal polymorphism in populations from two water bodies in the Volga region has been studied, 17 sequences are described. Polytene chromosomes of Endochironomus sp. (2n=6), having larvae morphologically similar to those of Endochironomus
albipennis Meigen, 1830 (2n=6) are described for the first time.