Insect growth-regulating effects of Withania somnifera in a polyphagous pest, Spodoptera litura

Treatment of sixth instar larvae and pupae of the polyphagous pest Spodoptera litura Fabr. (Lepidoptera: Noctuidae) with an acetone extract of leaves of Ashwagandha, Withania somnifera L. (Solanaceae), caused toxicity, molt disturbances, formation of larval–pupal, pupal–adult intermediates and adultoids. Our results suggest that W. somnifera acts as an insect growth regulator causing disruption of the endocrine mechanism regulating molting and metamorphosis.