The fauna of the blood-sucking insects in the Russian north-west. Characteristics of the ranges

The fauna of the Northwestern Region of Russia comprises 285 species of blood-sucking insects. Numbers of species of mosquitoes and lice in the Northwest constitute 40% of their total numbers in the Russian fauna; that of the biting midges, 38%; horse-flies, 35%; black-flies, 30%, and fleas, 1.9%. Representatives of the 4 families of the gnus complex, and also lice and fleas of the Northwestern Russian fauna possess ranges of 12 types, most of which include large part of the Holarctic or Palaearctic. 57 species (20%) of the species possess ranges of the Holarctic type; 82 species, or 28%, transpalaearctic ranges; 49 species, or 17%, Western and Central Palaearctic ranges; and 73 species, or 25%, Western Palaearctic ranges. The portion of the species (8) with the remaining types of ranges constitutes 19%. A synopsis of the groups of species with these types of ranges is given. Species with the ranges extending in the north to the tundra zone constitute 13%, species with ranges including the taiga zone, 60%, and species with the rest types of ranges, 27% of the fauna.