Efficacy of some plant extracts against the cowpea weevil Callosobruchus maculatus F. (Coleoptera: Bruchidae

Abstract

This study was carried out under laboratory conditions, during the period 2007- 2008, to study the effects of lantana, sheh (powder, water and ethanol extracts) and sesame oil against the cowpea weevil (Callosobruchus maculatus F.) to evaluate their effects against mortality, egg laying and the adult emergence. Statistical analysis of treatments against mortality of test insects showed that, the lantana leaves water extract was more effective than lantana ethanol extract and powder. Whereas Sheh ethanolic extract was more effective than both Sheh water extract and the Sheh powder. Analysis of effect of the result treatments on egg laying showed that, both the Lantana and Sheh powders were more effective than their counter parts water and ethanolic extracts. Concerning emergence of adults, the results of treatments showed that, the Lantana powder was most effective than other Lantana extracts. While Sheh powder and water extracts were more effective than Sheh ethanol extract. Sesame oil was used for comparison with the natural botanical extracts of both (lantana and sheh) to control Callosobruchus maculatus at different concentrations (0.15ml, 0.05ml, 0.1 ml and 0.2ml) and was effective against the test insect. The results of the study showed that, these botanical extracts have an efficacy against the cowpea beetles. Therefore, they can be used, in the future, as alternatives to chemical pesticides.