Chironomids (Diptera, Nematocera, Chironomidae) of the Malaya Sosva nature reserve

At the nature reserve Malaya Sosva 26 species of chironomids from 19 genus and 5 subfamilies are listed, the subfamily Orthocladiinae is the richest in species composition (14 species). There are 52% of the Holarctic species, 24% of the European-Siberian species, 20% of the Trans-Palearctic species, and one species probably has the Siberian-Far Eastern range. For the first time in Russia a very rare species from the subfamily Podonominae Lasiodiamesa gracilis is noted, for the first time in the West Siberia three species from subfamily Orthocladiinae are indicated: Corynoneura aurora, Rheocricotopus (Rheocricotopus) fuscipes, Tavastia yggdrasilia. The role of the chironomid’s larvae in the zoobentocenoses of the some water bodies and watercourses was studied. The total biomass of macrozoobenthos of the studied hydrological objects varied from 0.03 to 4.00 g/m2, averaging 0.03 g/m2. The average number was 0.82 thousand ind./m2, the minimum - 0.17 thousand ind./m2, the maximum -2.71 thousand ind./m2. The greatest contribution to the total biomass of benthic communities was made by chironomids, caddisflies and oligochaetes.