Sustained colonization of the black fly Simulium decorum Walker (Diptera: Simuliidae).

The black fly Simulium decorum Walker has been colonized for 16 generations (18 months) using an inexpensive larval rearing system. More than 90% of the females are induced with simulated twilight to oviposit on floating cork substrates. Eggs on corks have been successfully stored for up to 2 months at 0.5–1.5 °C. Female survival averages 87% for 4 days at 22 °C and 90–95% relative humidity. Mating in aspirator tubes results in nearly 100% insemination, whereas a cage mating trial resulted in only 26% insemination. Under crowded conditions where larvae are underfed, emerging males are smaller and mature fewer eggs. Though autogenous, nulliparous females readily blood feed on humans but do not mature additional eggs.