Toxicity of two plant powders as biopesticides in the management of Callosobruchus maculatus F. (Coleoptera: Chrysomelidae, Bruchinae) on two stored grain legumes

Abstract

Objective: The present study aimed to evaluate effects of leaf powder of Chenopodium ambrosioides (wormseed) and Adenia cissampeloides (snake climber) on insect populations and seeds weight loss percentage. Methodology and Results: Two leaf powders were applied at 2.5%, 5% and 7.5% (wt/wt). All bioassays were conducted at 27±2°C and 70±5%RH. Insect mortality was evaluated after 2, 4 and 6 days of exposure and the total progeny was assessed 34 days after. C. ambrosioides at 2.5% showed the best efficacy, recording 69.64% of mortality in Vigna subterranea groundnuts and 100% of mortality in Kerstingiella geocarpa one’s, 6 days after treatment. The lowest LC50 value after 6 days was obtained with A. cissampeloides applied at 2.37g/20g of V. subterranea groundnuts and with C. ambrosioides applied at 1.38 g/20g of K. geocarpa groundnuts. Conclusion and application of findings: Because of their effectiveness, the leaf powder of these plants could be recommended as grain protectant against C. maculatus.