Insecticidal potentials of plant oils against Callosobruchus chinensis (Coleoptera: Bruchidae) in stored chickpea

Pulse beetle, Callosobruchus chinensis L., is an important pest of stored chickpea and widely distributed in the world. Chemical insecticides and fumigants are common control tactics against pulse beetle, even though they have caused serious drawbacks. As an alternative control method, botanical compounds and their constituents have been successfully used against this pest. We tested the protective efficacy of 18 edible and non-edible oils in storage in ambient room condition. The efficacy was evaluated considering oviposition, adult emergence, seed infestation and seed weight loss caused by pulse beetle. All the tested oils effectively checked the oviposition, adult emergence, seed infestation and weight loss compared to control. However, the oils of neem, castor, karanja, and sesame at 4.0 to 8.0 ml/kg seed showed significant reduction of oviposition, and completely inhibited adult emergence, seed infestation and weight loss of chickpea seeds. The mustard oil could reduce the oviposition, adult emergence, seed infestation and seed weight loss at 8.0 ml/kg. Tested oils did not show any adverse effects on seed germination up to three months of storage. Therefore, neem, castor, karanja, and sesame oils can be used as environmentally safe management tactic for C. chinensis in protecting pulse seeds in store.