Tabanidae from the north of Sakhalin Island.

The studies were carried out on a deer farm in the Alexandrovsk-Sakhalinsk region, Sakhalin Island, Russian Far East, in 1982. 12 species of Tabanidae were collected from the deer and immediate environment (Hybomitra sexfasciata, H. montana montana, H. montana var. flaviceps, H. lapponica [H. borealis], H. tarandina, H. distinguenda contigua, H. arpadi, H. olsoi, H. nigricornis, Chrysops nigripes, C. suavis suavis and Haematopota pluvialis tristis), bringing to 21 the number of species of Tabanidae recorded on Sakhalin Island. Hybomitra montana montana and H. sexfasciata were the dominant species representing 36.80 and 30.36% of all flies found, respectively. The only other species recorded in considerable numbers were H. borealis, Haematopota pluvialis tristis and C. nigripes representing 9.47, 9.82 and 8.42% of the total, respectively. The tabanids were active from 10.45 h to 20.15 h. The lowest temperature for flight was usually 16.2°C and the optimal conditions were a temperature of 18.5°C, a humidity of 46-91% and a wind speed of 3.4 m/s. The nuisance caused by the flies was greatest during the last part of July and the first part of August. The total flight period lasted 1.5-2 months.