Bio-Efficacy of Clove Syzygium aromaticum against Pulse Beetle Callosobruchus chinensis

The pulse beetle Callosobruchus chinensis (Coleoptera: Bruchidae), is a significant pest of stored grains, particularly pulses, poses health and economic risks. The efficacy of botanical insecticides specifically clove against pulse beetles, reared on stored grains, was evaluated in this study. Laboratory bioassays were conducted to assess the effect of clove on % infestation of whole moong seeds, eclosion of adults, and the sex ratio. It was observed that though there was no significant difference in the % infestation in ‘control’ and ‘test’ conditions, there was a significant difference in the ratio of males to females that emerged in the two conditions. The mean sex ratio was 0.77:1 in ‘control’ and 1.05:1 in ‘test’ conditions. It indicates that it would consequently lead to significant reduction in the population buildup of pulse beetles owing to the lesser number of females that emerged in the test condition in which a clove was kept along with whole moong seeds. The results of this preliminary study are quite encouraging and indicate the potential of clove as a ready-to-use condiment in the management of pulse beetles in an effective, economical and eco-friendly manner. Further studies are in progress to evaluate the effect of clove in different forms on the various behavioural responses of this economically important pest of stored grains, which could help in its management in an integrated manner.