Toxicity of Jatropha Seed Oil to Callosobruchus maculatus (Coleoptera: Bruchidae) and its Parasitoid, Dinarmus basalis (Hymenoptera: Pteromalidae)

The susceptibility o f C. maculatus and D. basalis to Jatropha seed oil was evaluated un der laboratory c onditions. T he adults of C. maculatus and D. basalis had the same susceptibility to Jatropha seed oil but the parasitoid was relatively more susceptible than its host at all treatment levels. The oil was also r epellent to C. maculatus but its persistency declined from 15 to 60 days in storage. The eggs of C. maculatus were c omparatively more s usceptible t o t he Jatropha seed oil than those of the p arasitoid due to the protection afforded by the grain. However, the larvae and pupae of C. maculatus showed a relatively l ower susc eptibility t o the oil. It is p ossible to incorporate the oil in a well designed pest management p rogramme taking advantage of t he short p ersistency o f t he oil o n grains and its re latively ineffectiveness against the C. maculatus pupae developing i nside t he grai n.