The gonotrophic cycle in Simulium ochraceum.

Oogenesis in Simulium ochraceum is characterized in terms of distinct stages of follicular development following emergence, sugar feeding, and completion of a blood meal. Changes in the ovary following the first oviposition are also described. This black fly species was found to be anautogenous and exhibited gonotrophic concordance. The formation of follicular dilatations after oviposition followed a distinct pattern with traces of cellular debris evident up to 144 hours. The presence of fructose, as detected by the cold Anthrone test, indicated that both parous and nulliparous flies routinely imbibe nectars as part of their foraging behavior. The availability and frequent use of nectar may contribute significantly to longevity of parous flies, hence increasing their vector potential.