[Phenology of sandflies of the genus Sergentomyia in the Karshi Steppe (Phlebotominae)].

Phenological observations on sand flies of the genus Sergentomyia inhabiting the burrows of Rhombomys opimus from the Karshinskaya steppe were carried out for many years. The emergence of two mass generations of S. arpaklensis and S. grekovi was noted for the spring-summer period. In S. arpaklensis from oasis the appearance of the first individuals was noted mostly often in the II--III decade of May, the first peak of abundance--in the II--III decade of June and the second peak of abundance--early in August. In S. grekovi the appearance of the first individuals was observed at the end of April--the very beginning of May, the first peak of abundance--in the second half of May and the second peak--in the first half of September. During July--August the abundance of S. grekovi is rather low. Throughout the desert areas southward from oasis all phenological phenomena take place in both species ten days earlier than in oasis. S. arpaklensis is characterised by its very high abundance in oasis and in foothill loes plain, sharp fluctuations in the abundance both in seasons and years and by the prevalence of females over males during the active flight.