Efficacy of flavonoids in controlling Callosobruchus chinensis (L.) (Coleoptera: Bruchidae), a post-harvest pest of grain legumes

The effects of partially purified flavonoids obtained from Calotropis procera (Ait.) R. Br. and six standard flavonoids on the adults and eggs of Callosobruchus chinensis (L.), reared on mung beans (Vigna radiata L.), were studied. All flavonoids were toxic to adults and eggs depending on dose and exposure period. Flavonoids obtained from C. procera showed the highest contact toxicity followed by standard quercetin, rutin and quercitrin at 10 mg mL-1 doses in filter paper diffusion assay. Significant reduction in oviposition was found for all flavonoids at the doses of 5 and 10 mg mL-1 on grains in plastic jars. Flavonoids also showed an ovicidal effect on bruchid eggs as well as affecting the number and weight of the emerging adults as a function of concentration.