Comparative bio-efficacy of Bacillus thuringiensis var. kurstaki against Spodoptera litura (Fabricius) on different host plants*

A field - cum - laboratory trial was conducted for the purpose of studying the comparative bio-efficacy of Bacillus thuringiensis var. kurstaki against Spodoptera litura (Fabricius) on three host plants viz., castor, cotton and groundnut. The result showed that there was no significant influence of host plants on bio-efficacy of B.t., eventhough B.t. on cotton registered a higher larval mortality as compared to groundnut and castor. This might be happened due to variation in physio-biochemical status like alkaline surface of plant favoring the pathogenicity of the B.t.