Laboratory studies on the larvicidal activity of Bacillus Sphaericus-2362 and 2297 against Anopheles dirus and Anopheles annularis

The larvicidal efficacy of Bacillus sphaericus -2362 and 2297 was tested against larvae of Anophales Dirus (Mudon strain) and Anophales annularis (DDT-resistant strain from Sittwe), using the method of Dubitskij (1) with some modifications. The results showed that although both the strains of B.sphaericus were effective larvicides, strains 2363 was found to be much more potent than strain 2297. Anopheles dirus was also found to be more susceptible than An.annularis. Larval cadavers were found to play an important role in the maintenance and recycling of B.sphaericus-2362.