Grain Protectant Efficacy of Certain Plant Extracts Against Rice Weevil, Sitophilus Oryzae L. (Coleoptera: Curculionidae)

Abstract

In the present study, ethanol extract of Clerodendrum inerme L. (Verbenaceae), Withania somnifera L. (Solanaceae), Gliricidia sepia L. (Fabaceae), Cassia tora L. (Caesalpiniaceae) and Eupatorium odoratum L. (Asteraceae) were evaluated for their efficacy on mortality and progeny production of rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae). Adult insects were exposed to the 2.5 and 5% extracts treated wheat and mortality was assessed after 1, 2, 7, 14 and 21 days. Subsequently, all adults were removed and the treated grains remained at the same conditions for an additional 45 days. After this interval, the commodity was checked for progeny production. All extracts, the beetles mortality was increased in dose dependent manner. Results indicated that C. inerme and W. somnifera extracts were more effective than G. sepia, C. tora and E. odoratum against adult insects. Interestingly, the progeny production (Fl) was complete by suppressed even in lowest dose. It was concluded that both C. inerme and W. somnifera can be used for the protection of stored wheat from infestations of S. oryzae.