Efficacy of native isolates of entomopathogenic bacterium against cabbage butterfly (Pieris brassicae linn.)

Three isolates of Bacillus licheniformis were identified from local soil samples of Prayagraj agro-climatic regions, and bioassay studies were performed to corroborate the insecticidal activity of the isolates against the larval instars. Soil samples were also examined for their pedological characteristics. It was found that all the concentrations were significantly different from control in causing mortality on both 1^st and 3^rd instar larvae. While Bl(cht) was found to be the most effective isolate in causing larval mortality. Studies on relative toxicity of isolates showed that Bl(cht) was found to be most toxic, causing 50% mortality of 1^st instar larvae at a concentration of 2 x 10⁴ cfu/ml. In the case of 3^rd instar larvae, Bl (am) and Bl (cht) both were found to be toxic at 2 x 10⁵ cfu/ml concentration. Thus, Bacillus licheniformis can be looked upon as a successful candidate as a biopesticide, an alternative to synthetic pesticides with reduced chances of resistance and multiple beneficial impacts to crops in the field of agriculture as well.