Daily activity of Tabanidae in the Caucasus.

The daily activity of Tabanidae (Diptera) was studied in the submountain region of the East Caucasus, district Ismailly, NE Azerbaijan SSR at an altitude 900--1000 m. Tabanidae were collected by the unbaited canopy trap on 8 and 12 July 1976. Females were active from 9 a. m. to 7 p. m., the diurnal biting activity is characterized by a one peak curve with a conspicuous peak of activity between 4 p. m. and 6 p. m. It is suggested that the temperature, relative humidity and the thermic mountain wind are the decisive factors influencing the late afternoon peak of activity. Mating activity of Tabanus unifasciatus at sunrise and of Philipomyia aprica at sunset were observed.