Chromosomal Polymorphism of Malaria Mosquitoes of Karelia and Expansion of Northern Boundaries of Species Ranges

Chromosomal variability in peripheral populations of malaria mosquitoes of the Anopheles genus (Diptera, Culicidae) inhabiting the territory of Karelia has been studied. The modern northern limits of the ranges inhabited by sibling species of malarial mosquitoes An. beklemishevi, An. daciae, An. messeae s. s. and An. maculipennis were established. After 2010, the boundary of distribution of malaria mosquitoes shifted northward by 170 km, from the 65th parallel to the Arctic Circle. Inversion heterozygotes XL₁, XL₂, 2R₂, 3R₁, and 3R₅ were found in peripheral populations of An. beklemishevi. Peripheral populations of An. messeae s. s. were homozygous for inversion of sex chromosome XL₁ and differed in the frequencies of autosome inversions from the middle taiga populations. The frequency of heterozygotes for autosomal inversions 2R₁, 3R₁, and 3L₁ increased in populations at the edge of the species range. Chromosomal variability in peripheral populations contributes to the dispersal of malaria mosquitoes in high latitudes under warming climate conditions.