The parasitoids Dinarmus basalis Rond. (Hymenoptera: Pteromalidae) and Eupelmus vuilleti Crwf. (Hymenoptera: Eupelmidae) develop mainly on relatively old larvae and pupae of Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) found in cowpea seeds. Therefore, it is possible to consider biological control against C. maculatus using these natural enemies. The intrinsic rates of increase for C. maculatus and the two parasitoids were determined during the dry season in the sub-humid area of Bobo-Dioulasso, Burkina Faso, from January to July 1995. Functional response was also analysed for D. basalis and E. vuilleti. At the beginning of the dry season, the cowpea weevil and both its natural enemy species had limited intrinsic rates of increase, attributed to the relatively low temperatures and low relative humidity thatprevail during this period. In March, when temperature and relative humidity began to rise, conditions were optimum for their reproduction and development. Dinarmus basalis showed the higher intrinsic rates of increase and parasitism through the study period. Analysis of the functional response revealed that fecundity and potential for parasitism of both parasitoids were density-related and varied with climatic conditions. However, D. basalis showed a more efficient response. This study has shown that the variations of climatic conditions such as temperature and relative humidity during the dry season significantly influence the development and reproduction of C. maculatus and its parasitoids. Dinarmus basalis appeared to be the better biological agent in controlling C. maculatus.