Sitophilus zeamais and Prostephanus truncatus are the major pests of maize and can simultaneously infest maize grains during storage. This study aimed to evaluate the effect of interspecific competition on the feeding and reproductive behavior of P. truncatus and S. zeamais over a six-month period. To achieve this, maize grains were simultaneously infested with the two pests at different ratios, representing the following treatments: 25 P. truncatus – 25 S. zeamais, 25 P. truncatus – 50 S. zeamais, and 50 P. truncatus – 25 S. zeamais. A significant increase in the number of S. zeamais offspring was observed compared to P. truncatus. Moreover, S. zeamais caused the highest rates of grain perforation and weight loss. Within the same maize stock, the feeding and reproductive behavior of S. zeamais did not appear to be affected by the presence of P. truncatus. The mixed-population treatment of 25 P. truncatus – 50 S. zeamais caused the most damage, whereas the 25 P. truncatus – 25 S. zeamais treatment resulted in the lowest grain weight loss and perforation rates. These results indicate that interspecific competition influences infestation dynamics, damage levels, and weight losses caused by these two pests.

Shea kernels are generally stored by Burkinabè households. A prospective study conducted in Ziro province revealed the damage caused by insects. The objective of this study was to inventory the pests associated with shea kernel stocks. Samples of shea kernels were collected from farmers’ stocks in three localities of the province over a six-month period. At each period, 4 samples were taken from each locality to constitute 12 batches that were brought to the Laboratory of Fundamental and Applied Entomology of the Joseph KI-ZERBO University. Each batch was analyzed and kept for insect emergence monitoring for 45 days. Six (06) species of predators were identified, among which Ephestia cautella (Walker) was the most abundant (87.33% of individuals). Four (04) species of the order Coleoptera, were recorded with proportions of individuals lower than 4%. Bracon hebetor (Say), a parasitic Hymenoptera, was recorded with a proportion of 7.26%. The rate of perforation of kernels, which was significant at the beginning of storage (28.87%), increased progressively to reach a maximum of 57.73% after six months of storage. It is important to study the behavior of H. hebetor toward E. cautella in order to clarify its status and possibly consider the implementation of a biological control against this pest.