Autogeny in Canadian Simuliidae (Diptera), with some experiments on rate of oögenesis

Abstract

Newly emerged females of 25 simuliid species were studied, 19 of which were maintained on dry sucrose and water to determine whether they could mature eggs autogenously. Females of nine species with reduced mouthparts and those of eight species with well-developed mouthparts proved to be autogenous, the latter group being presumably anautogenous for eggs cycles beyond the first. Females of the eight remaining species showed obligate anautogeny, requiring blood for any egg production. The literature indicated at least 19 Canadian simuliid species with obligate autogeny and at least 11 with facultative autogeny. The rate of ovarian development at different temperatures was examined in newly emerged females of 11 species and the completion of oögenesis varied from less than 2 days to 2 weeks in different species and in different females within species.