A serial dilution of the stock solution involving the dissolution of 100 mg of the sample (Clove oil) in 100 ml of ethanol was prepared to obtain four different concentrations . Thirty grammes (30 g) of the cowpea seeds of a susceptible variety (Ife-Brown) were weighed into each of six 1 L Kilner jars. Using a micro syringe, 1 ml of each concentration was applied to the cowpea seeds and shaken for 3 minutes to allow effective coverage of the surface. The fifth jar received only ethanol as a negative control while the sixth jar contained pirimiphos-methyl as positive control. The cowpea seeds in the jars were infested with ten 1-2 day old C. maculatus and the experiment was laid out in a Completely Randomized Design (CRD) with four replications. Mortality of adult C. maculatus was recorded at 24, 48 and 72 hours after infestation and corrected with Abbott's formula . Data were expressed in percentage. PT= Po -Pc x 100 100 -Pc Where PT is the corrected mortality (%) Pc is the control mortality (%) Po is the observed mortality (%)