Efficacy of some plant species for the control of cowpea weevil (Callosobruchus maculatus) and maize weevil (Sitophilus zeamais)

The influence of leaf powders of Vitex grandifolia and Dracaena arborea incorporated into maize and cowpea flour on the survival of maize weevil (Sitophilus zeamais) and cowpea weevil (Callosobruchus maculatus), respectively was tested. Survival of adult beetles of maize and cowpea weevil was least on cowpea (10 g) and maize (10 g) flour treated with 3 g V. grandifolia (3.30-20%, 6.70-20%, respectively) and 3 g D. arborea (3.300-13.3%, 0.0-3.3%, respectively) compared to other treatments, which included different concentrations of the leaf powders. V. grandifolia was inhibitory to mean adult emergence of C. maculatus (7.00-9.33) and S. zeamais (8.00-9.67) compared with the control (15.00). However, D. arborea did not differ from the control. It is concluded that V. grandifolia has great potential for use as a plant-based biopesticide for controlling both weevil pests.