Evidence of multiple mating and hybridization in Simulium damnosum s.l. (Diptera : Simuliidae) in nature

Beakers with aeration were used to rear individual (single) egg batches of Simulium damnosum (Theobald) s.l, to larvae and adults. Chromosomal analysi s of the progeny of individual females indicated that multiple mating occur red within the S. damnosum complex and that hybridization occurred between S, damnosum s.s. and S. sirbanum (Vajime & Dunbar) in nature. These results indicate that possibly more extensive hybridization may be taking place in some areas of the Onchocerciasis Control Program than previously reported. Dramatic changes in the rates of hybridization among members of the S. dam nosum complex possibly may lead to the formation of new cytotypes.