Bioefficacy of powdery formulations based on kaolin powder and cashew (Anacardium occidentale L.) balms to control Callosobruchus maculatus F. (Coleoptera, Chrysomelideae: Bruchidae) in stored cowpea (Vigna unguiculata L.)

In this study, the bioefficacy of the powdery formulations were evaluated. Thus  powdery insecticide Antouka®, kaolin powder and powdery formulations based on kaolin powder and various cashew balms were tested against, cowpea bruchid in storage. For each balm, it was formulated 10 g of powdery formulation, which were obtained with 10 g of kaolin and 1 mL of cashew balm. Antouka® insecticide was applied at recommended dose; powdery formulations were tested at 0.5 g; 1 g, for 50 g of cowpea seeds in jars. Twenty (20) cowpea weevils at 24 h old were  introduced in each jar. The jars, covered with wire mesh, were kept outdoors during forty five (45) days using a randomized block design with four replicates. Therefore, parameters of mortality and F1 progeny of Callosobruchus maculatus , weight losses, seeds damaged and germination rate were assessed. Results obtained indicated that Antouka® insecticide and the formulated powders caused a significant  mortality rate and improved the germination rate of seeds. Nevertheless, the cold extracts had less seeds damaged than hot extracts. F1 progeny decreased with  increased dose, (25.50±7.96 insects to 44.50±7.67 insects for 0.5 g; and  11.25±4.62 insects to 29.50±3.22 insects for 1 g). According to calculated LD50 and their confidence intervals, formulated powders have significant toxicity on C. maculatus . These results revealed the bioefficacy of powdery formulations. They can be recommended as alternatives insecticides. Keywords : Callosobruchus maculatus , cowpea, bioinsecticides, toxicity, Benin.