Biological activities of terpenes against pulse beetle, Callosobruchus chinensis (Coleoptera: Bruchidae)

Two terpenes, α-pinene and β-caryophyllene were investigated for repellent, insecticidal, ovipositional and egg hatching inhibition its activities against pulse beetle, Callosobruchus chinensis (Coleoptera:Bruchidae). α-Pinene and β-caryophyllene repelled bruchid adults in choice oviposition assay .α-Pinene and β-caryophyllene caused both fumigant and contact toxicity in C. chinensis adults in a concentration dependent manner. These two terpenes reduced oviposition in C. chinensis adults significantly when treated with sublethal concentrations by fumigation and contact method both. Reduction in oviposition was more when terpene compounds were applied by contact method than fumigation method. B oth terpenes significantly reduced F1 progeny emergence, damage and weight loss in grains in chronic toxicity assay. Reduct ion in F1 progeny emergence, damage and weight loss in grains was more pronounced in case of β-caryophyllene than α-pinene. Application of these two terpenes showed no effect on germination of seeds. Present study suggests that α-pinene and β-caryophyllene can be useful as promising agent in insect pest management programme. Key words: α-Pinene, β-Caryophyllene, oviposition deterrence index, hatching inhibition rate