INFLUENCE OF TEMPERATURE AND HUMIDITY ON POPULATIONS OF CALLOSOBRUCHUS-MACULATUS (COLEOPTERA, BRUCHIDAE) AND ITS PARASITOID DINARMUS-BASALIS (PTEROMALIDAE) IN 2 CLIMATIC ZONES OF BURKINA-FASO

Callosobruchus maculatus (Fabricius) develops in the seeds of Vigna un guiculata in the Sahel region of Africa. The reproductive activity of this species and the development of its offspring were studied during the dry season at Ouagadougou and Bobo Dioulasso (Burkina Faso), two z ones with different climatic conditions. The length of imaginal life o f the females and the developmental time varied with changes in climat ic conditions, the lowest values for both parameters being found at th e end of the dry season when temperature and humidity increased. In th e two zones, variations in the density of the bruchid populations have been studied in experimental stores. The density of the bruchid popul ation was low at the beginning of the study and increased when tempera ture and humidity rose. The introduction of Dinarmus basalis (Rondani) adults to the stores caused a significant reduction in the numbers of C. maculatus adults. The density of the D. basalis populations was lo w from December to February and increased when temperatures and then h umidity became higher. The increase of the D. basalis population and t he rate of parasitism were greater at Bobo Dioulasso than at Ouagadoug ou. Laboratory studies have demonstrated that fecundity, duration of a dult life and developmental times depend on humidity. This study has s hown the importance of local climatic conditions on parasitoid reprodu ction and development and also in the control of bruchid populations i n stores.