Synergism between wild-type Bacillus thuringiensis subsp. israelensis and B. sphaericus strains: A study based on isobolographic analysis and histopathology

► Joint action of different toxins confer resistance problem in mosquitoes. ► Synergism improved toxicity of wild-type Bti and Bs strains. ► Isobolographic analysis distinguished synergistic and antagonistic mixtures of Bti and Bs. ► Histopathology of larval midgut revealed improved speed of kill of Bs toxins.