In this work, bioassays were carried out in laboratory conditions (average
temperature 26+/-2 C) to test ten strains of Bacillus sphaericus,
isolated from Brazilian soils against third instar larvae from anopheline
species recorded as malaria vectors in Amazonian - Anopheles
nuneztovari and An. darlingi. With the former mosquito, three
strains - S2, S20 and S46 showed relative activity, in 24 and 48 hr
exposure to the B. spahericus strains. With the latter only the S2
and S20 were effective in the 48 hr reading. The studied strains that
showed the most adequate response in the Amazonian region were S2 and S20
showing broader and more efficient results. Therefore, S2 was the most
effective when the 24 and 48 hr readings were considered, because it showed
the greatest relative activity values.
