Comparative susceptibility of different legume seeds to infestation by cowpea bruchid Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae)

Abstract

The comparative susceptibility of seeds often legumes to infestation by Callosobruchus maculatus was studied in choice and no-choice experiments. Cowpea, garden pea and pigeon pea seeds recorded the significantly highest number of eggs oviposited and percentage adult emergence, the shortest developmental period, highest susceptibility indices and the highest weight loss. In a choice experiment, treatments which had a cowpea mixture recorded the maximum number of eggs deposited on that legume. The order for ovipositional preference for all legume seeds remained almost the same irrespective of the host on which C. maculatus had been reared. Also, there was no association between the seeds preferred for oviposition and culture on which the bruchid was reared. Cowpea and pigeon pea seeds were found to be highly susceptible to C. maculatus, whereas common bean, black gram and chickpea seeds were the least susceptible.