Impact of natural products, spinosad and emamectin benzoate on <i>Callosobruchus chinensis</i> (L.) (Coleoptera: Chrysomelidae)

Pulse beetle is one of the most damaging insect pests of stored grains, mainly in tropical and sub-tropical regions of the world. Under the present study, ten plant-derived powders and two insecticides were evaluated against Callosobruchus chinensis in stored chickpea. All treatments significantly increased adult mortality compared to the control. Among botanicals, Ageratum conyzoides and Lantana camara exhibited the highest efficacy. Both spinosad and emamectin benzoate achieved 100% mortality; however, spinosad exhibited a more rapid onset of action. A. conyzoides and L. camara significantly reduced beetle emergence, grain damage and weight loss and preserved seed germination, while Murraya koenigii, Azadirachta indica and Eucalyptus grandis were found to be less effective. Both insecticides were highly effective in suppressing population growth and minimising grain damage, weight loss and germination loss. In terms of overall efficacy, spinosad and emamectin benzoate emerged as the most effective treatments, followed closely by extracts of A. conyzoides and L. camara. These findings suggest that the selected botanicals and novel insecticides are effective candidates for managing C. chinensis in stored pulses, provided their residual dissipation is further evaluated.