Aspects of the biology of female Chrysops univittatus (Diptera: Tabanidae) in southwestern Quebec

In observations on adults of Chrysops univittatus Macq. in south-western Quebec in 1980 and 1981, females were most abundant in late July and early August. Of the totals in baited (with carbon dioxide) and unbaited canopy traps, 60% of the nulliparous and 77% of the parous females were taken in baited traps. As determined by a cold anthrone test, 73% of the females had fed on nectar. For both nulliparous and parous females, 96% contained sperm. This species is considered to be anautogenous, and only one gonotrophic cycle was recorded following ovary dissection. The number of ovarioles was correlated with body size (as determined by wing length).