Abstract: The powders of the leaves of H. suaveolens, O. gratissimum and Azadirachta indica were assessed for their daily effect against Sitophilus zeamais Mots infesting maize grains (Zea mays) and Callosobruchus maculatus Fab infesting cowpea seeds. The powders were tested at 1.5, 2.5 and 3.5 g/80 g of food materials. The results revealed that, daily mortality of Sitophilus zeamais was dependent on concentration with maximum kills occurring on day 3 of exposure. Mortality of S. zeamais was either absent or minimal on the first two days of exposure. This however, contrasted the pattern of mortality exhibited by Callosobruchus maculatus which showed a negative daily mortality with increased concentrations compled with maximum daily mortality occurring in the first two days of exposure.