Effects of sun exposition on population of bruchids in cowpea (Vigna unguiculata (L.) Walp) storage system in Niger

The effect of the exposition to the sun light on the population build-up of Bruchidius atrolineatus Pic. (Coleoptera: Bruchidae) and Callosobruchus macudatus Fab. (Coleoptera: Bruchidae) and their parasitoids in cowpea (Vigna unguiculata (L.) Walp) storage system was studied. Pods were divided in five sunlight-exposure treatments. Each treatment was implemented one week before the following treatment and exposed to the sun light. The results showed that the infestation level depended on the time of exposition to the sunlight. When increasing the exposition time, the number of eggs laid and the number of bruchid and parasitoid adults decreased drastically. Thus, the exposition to the sun light of the pods and seeds seemed to be an excellent and simple method to prevent bruchids infestation during the storage of cowpea beans pods and seeds.