Evaluation of Insecticidal Potentials of Five Plant Extracts against the Stored Grain Pest, Callosobruchus maculatus (Coleoptera: Bruchidae)

Plant based insecticides are considered among the most economic and ecofriendly chemicals for the protection of plants and stored grains. The cowpea weevil ( ) causes more than 90% damage to sored grains in three to six months. The current study investigates insecticidal potentials of five selected botanicals: , and They are explored at six different concentrations (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0%) against and compared to effects of distilled water which is used as a control. Toxicities of 3%(V/V) extracts of and against were 100%, 86.11%, 80.56% and 72.22%, respectively. Maximum mortality was caused by and (100%), followed by (82%), whereas minimum mortality was observed in (64%) at 2.5%. Several phytochemicals, alkaloids, saponins, diterphenes, phytosterol, flavonoids and phenols were identified in and while few were present in Phytosterol was present in greatest abundance. Saponins were only detected in aqueous extracts of and Taken together, these results indicate the utility of , and as potential botanicals to control pest beetle and cowpea weevil.