Evaluation of acute lethal response of Corcyra cephalonica to Bacillus thuringiensis Berliner Var. kurstaki, strain ABTS-351, an isolate of strain HD-1

Bacillus thuringiensis (Bt) is the most successful among other microbial pesticides. The microbe formulations are being implemented in many IPM programs. Among many subspecies, Bacillus thuringiensis Berliner Var. kurstaki subspecies is specifically used against lepidopteran pests. Its strain ABTS-351 (Btk ABTS-351) is the active biocide product in several new Bt formulations and is essentially an isolate of strain HD-1. Efficacy screening is imperative due to chances of pest insects developing resistance to Bt formulations. This study was conducted to characterize Btk ABTS-351 strain for potent insecticidal activity against Rice moth, Corcyra cephalonica larvae in local conditions. The LC₅₀ value (with 95% confidence limits) of Bt on C. cephalonica 4th instar larvae for 24 hr was 65.813 (52.946 – 85.689) mg/mL. This value is comparatively higher than those observed in other lepidopteran larvae. The toxicity and mode of action of this formulation can be used efficiently to manage stored grain pests like C. cephalonica, and also has the potential to be combined with other compatible IPM control strategies.