Laboratory experiment was carried out to evaluate the efficacy of Stembark and pod powders of locust bean (Pakia biglobossa) and their appropriate concentration for the management of cowpea weevils (Callosobruchus maculatus F.). Spintor (0.125%) and dust (0.125 g) was used a positive control and untreated cowpea seeds serving as negative control. The experiment was laid in Completely Randomized Design (CRD) comprising of Stem bark powder (1 g, 3 g and 5 g), Pod powder (1 g 3 g and 5 g), spintor 0.125% Dust (0.125 g) and control. These were applied to 100 g healthy cowpea seeds and repeated three times. Contact activity of the plant products were evaluated and data collected were subjected to analysis of variance (ANOVA) using SPSS software (version 23) and means were separated using NDMRT at 1% and 5% probability level. The results showed that higher concentration (5 g/100g) of plant products significantly (P<0.05) caused mortality of C. Maculatus after 24 (2.33), 48 (2.66), 72 (2.66) and 96 hours (3.00) by contact toxicity compared to other treatments. Similarly, higher concentration (5 g/100g seed) of the pod powder significantly (P<0.05) decreased oviposition (3.67), adult emergence (3.66), percentage seed damage (1.73%), number of exit holes (6.33) and weight loss (1.03%) compared to untreated cowpea seed that record 58.00,  54,67, 19.67%, 56.33 and 13.87%, respectively. It was concluded that germination of the treated seeds was not affected negatively. The Pod powder of P. biglobossa could be recommended as suitable alternatives to chemical pesticides to be used as contact protectant against C. maculatus on stored cowpea seeds.

Laboratory experiment was conducted to determine the insecticidal activity of leaves and stem bark powder of Sodom apple (Calotropis procera) and optimum concentration for the management of maize weevil (Sitophilus zeamais). Actellic dust was used a positive control and untreated maize seeds serving as negative control. The experiment was laid in Completely Randomized Design (CRD) comprising of Leaves powder (1 g, 3 g and 5 g), stem bark powder (1 g 3 g and 5 g), Actellic dust and control. These were applied to 100 g healthy maize seeds and repeated three times. Contact activity of the plant products were evaluated and data collected were subjected to analysis of variance (ANOVA) and means were separated using NDMRT at 1% and 5% probability level. The results showed that the application of 5 g/100g leaves significantly (P<0.05) caused highest mortality of adult S. zeamais at 24 (2.33), 48 (2.66), 72 (2.33) and 96 (2.00) hours by contact toxicity comparable to other treated seeds. Similarly, maize seeds treated with 5 g /100 g of the leaves powder significantly (P<0.05) decreased Oviposition (3.33), Adult emergence (3.00), Percentage grain damage (3.67%), Number of exit holes (3.33) and Weight loss (1.63%). Germination of the treated seeds was not affected negatively. The 5 g of leave of C. procera could be recommended as suitable alternatives to chemical pesticides to be used as contact protectants against S. zeamais on stored maize seeds.