Evaluation of Efficacy of Neem and Datura Products in the Control of Cowpea Weevil Callosobruchus maculatus F. (Coleoptera: Bruchidae)

Abstract

The potential usage of ethanolic extracts of neem and datura seeds in addition to the neem seed oil as pest control agents was investigated under laboratory conditions against the cowpea weevil (Callosobruchus maculatus F.). Evaluations were based on the oviposition repellent effect, insecticidal and the effect on development of C. maculatus (F.). The investigation was also extended to cover the evaluation of the loss in weight of cowpea seeds. The concentration extracts that used were 2.5%, 5% and 10%. The results of this investigations showed that there was a significant repellent effect on egg laying. Insecticidal activities of this extracts were observed during the first four days of the experiment in particular. Post-oviposition treatments of cowpea seeds with the neem oil, ethanolic extracts of neem and datura seeds, showed strong inhibition to the egg viability and percentage of adult emergence. The results generally indicated the order of effectiveness: neem seed ethanolic extract > neem oil > datura seed ethanolic extract. Also the extracts decreased the percentage of weight loss of treated cowpea seeds. The results reported here indicated the good potential of these plants as promising alternatives to synthetic pesticides, and the mode of efficacy was discussed.