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

Chromosomal variability in peripheral populations of malaria mosquitoes of the genus Anopheles (Diptera, Culicidae) inhabiting the territory of Karelia was studied. The modern northern limits of the ranges of sibling species of malarial mosquitoes An. beklemishevi, An. daciae, An. messeae s. s. and An. maculipennis were established. After 2010, the distribution boundary 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 area. Chromosomal variability in peripheral populations contributes to the dispersal of malaria mosquitoes in high latitudes under warming climate conditions.