Evaluation of relative susceptibility of Callosobruchus chinensis Linn. on five different stored pulse seeds

The pulse beetle, Callosobruchus chinensis (L.) (Coleoptera : Bruchidae), is a worldwide insect pest that infests pulses in the fields and seeds in storage. An investigation has been conducted on the life history and ovipositional preference, nature of damage caused by Callosobruchus chinensis reared on five different pulses through two successive generations. Kidney bean preferred most for oviposition followed by cowpea, black gram, small pea and green gram but adult survival rate is low in kidney bean. The adults exhibited a marked preference for smooth, large surfaced and well-filled seeds for oviposition. The pulses selected for the investigation are initially infested by the insects, but degree of infestation varied among the pulses. Thus susceptibility varies in different pulses. The order of susceptibility as per susceptible index was cowpea > green gram > small pea > black gram. Whereas kindey bean found resistant. Damage caused by the beetle also varied and the order is cowpea > green gram > black gram > small pea > kidney bean. This is due to the varied responses of the insect to different host seeds for oviposition and their appropriateness for the successful completion of the life cycle