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