A mosquito-virulent Bacillus sphaericus in adult Simulium damnosum from northern Nigeria.

From newly emerged adult Simulium damnosum from Kaduna River, Northern Nigeria, a mosquito-virulent strain of Bacillus sphaericus was isolated. In another four cases non-virulent B. sphaericus were present. The isolate exerted a LC50 of 50 spores/ml for Culex pipiens L4-larvae and was less virulent for Anopheles stephensi (400 sp/ml) and Aedes aegypti (800 sp/ml).