| A total of 3408 strains of Bacillus thuringiensis were collected from 1448 soil samples in 10 Brazilian states, four different geographical regions, covering 96 counties. These strains were evaluated against Spodoptera frugiperda (J.E. Smith) larvae. Only 62% killed between 81% and 100% and 1758 caused no mortality. Highest proportion of efficient strains (larval mortality above 75%) was found from the total isolated per region in the South Region (16.6%), followed by Western Central (3.1%), Southeast (1.1%) and Northeast Region (0.4%). |
