Dynamique des populations naturelles de bruches et de leurs parasitoïdes nympho-larvophages en situation expérimentale de stockage de niébé en zone guinéenne

Population Dynamic of Natural Bruchids and their Larval and Pupae Parasitoids in Experimental Cowpea Storage in Guinean Zone. Population dynamic of natural bruchids and their parasitoids were analysed in Guinean subtropical climatic conditions and in an experimental storage situation in Togo. Emergence of insects from cowpea samples collected from 5 localities sited between 6 and 8° north latitude gave the opportunity to list 3 species of bruchids: Callosobruchus maculatus (F.), Callosobruchus rhodesianus (Pic.) and Bruchidius atrolineatus (Pic.). B. atrolineatus and C. rhodesianus under go reproductive diapause and die in the storage. C. maculatus was the only species which remained in cowpea storage. The last two species have inverse distribution. B. atrolineatus seemed to be more abundant in the northen zone whereas C. rhodesianus is important in the southern one. Dinarmus basalis Rond. (Hymenoptera: Pteromalidae) was the larval and pupae parasitoid of bruchids found in our samples. However its initial population was low. The presence and maintenance of D. basalis populations in stores restricted cowpea bruchids development.