Cowpea, Vigna unguiculata (L.) Walp. (Fabaceae) is a legume that plays an important role in the dietary balance of tropical populations. These seeds are an important source of protein that can make up for the lack of animal protein in food rations in sub-Saharan countries. The Bruchidae family (Bruchidius atrolineatus, and Callosobruchus maculatus) occupies first place in the diversity of insects that have adapted to cowpea stocks. Bruchidius adults colonize cowpea crops from the start of flowering. Females lay eggs on the pods as soon as they begin to form. Larvae and pupae are therefore already present in the harvested products, which are stored in granaries. The larvae penetrate the seeds, at the expense of which they carry out their embryonic post-development. The damage caused by this insect pest can be considerable if no protective measures are taken. To prevent damage caused by C. maculatus during cowpea storage, farmers generally expose seeds and pods to sunlight for several days before storing them. The aim of this work was to study the impact of sun pre-exposure and cold pre-treatment on the different development stages of C. maculatus. The results obtained show that C. maculatus adults are more sensitive to solar radiation than to cold conservation; in the case of pre-exposure to the sun, a 100% mortality rate is observed from 1 h onwards, whereas the same result is obtained at 2h30 min in the case of cold pre-treatment. On the other hand, cold had a greater effect on eggs, L2 larvae and L4 larvae than sunlight. For eggs, a 30 minutes cold pre-treatment gives a 100% mortality rate, whereas pre-exposure to the sun requires 45 minutes. L2 larvae and L4 larvae gave respectively 100% mortality from 2h and 2h30mn cold; while for sun pre-exposure respective durations of 2h30 min and 3h were recorded.