Abundance and seasonal distribution of Tabanidae in a temperate and in a subarctic locality of Québec

The seasonal distribution of tabanids at Trois-Rivieres (in the temperate zone of Quebec) and the Lake Delorme area (in the high subarctic) was studied in 1977 and 1978. Of the 43 species collected in southern Quebec, Chrysops aestuans Wulp was the dominant species, followed by Hybomitra pechumani Teskey & Thomas, H. lasiophthalma (Macq.), C. frigidus O.-S. and H. zonalis (Kby.). The flight period began in mid-May, with the greatest abundance from mid-June to mid-July. Five phenological groups were distinguished by first appearance of the species and their respective abundance peaks. In the Lake Delorme area, 20 species were identified, of which 12 were also present in the southernmost area. H. arpadi (Szil.) was the dominant species, followed by C. furcatus Wlk., C. excitans Wlk. and H. zonalis. The flight period began on 8 July, with most activity during the 3rd week of July.