Abstract

Previously, other authors recognized that female mosquitoes Culex territans Walker were active at relatively low temperatures after overwintering and were able to complete their first gonotrophic cycle at temperatures close to +4°C. The present study demonstrated relatively high tolerance of diapausing Cx. territans females, collected from near-entrance parts of caves, to short-term freezing (20–30 min at −9…−11°C). The proportion of individuals that survived short-term freezing in an experiment was higher among Cx. territans than among Cx. pipiens/torrentium collected simultaneously with Cx. territans from the same hibernacula. The difference between Cx. territans and Cx. pipiens L. was statistically significant, while that between Cx. territans and Cx. torrentium Martini was nonsignificant, despite the similar proportions of survivors among Cx. pipiens and Cx. torrentium. The new data give direct support to the hypothesis that adult females of Cx. territans are adapted to low temperatures. Obviously, there are special physiological mechanisms in overwintering Cx. territans females underlying their tolerance to short-term freezing.