The suitability of some plant products (leaf powders and volatile oils) in protecting cowpea seeds from attack by Callosobruchus maculatus F. during storage was evaluated at a range of 0.5–4 g powder and 0.5–30μ1 for oils. Oils of the plants studied: Lantana camara L., Cymbopogon citratus (DC) Stapf., Eugenia uniflora L. and Lippia adoensis Hoschst. were more potent than their respective powders in reducing or inhibiting oviposition and adult emergence. Effectiveness of the oils as protectants for stored cowpea in decreasing order is: L. adoensis = C. citratus > L. camara and E. uniflora. Only the powdered leaves of E. uniflora and L. adoensis were effective in providing a high level of bruchid control. However, dressing with all the oils and powder of E. uniflora left the seeds fresh at 54 days after treatment. The significance of these findings in protecting cowpea against the storage pest is discussed.
