The cowpea is a vital crop for low-resource farmers in the Sahel, but post-harvest losses due to insect pests remain a major challenge. Callosobruchus maculatus (Fabricius, 1775), is the primary pest responsible for most of the damage to stored cowpeas. Recently, Trogoderma granarium (Everts, 1898) was found infesting cowpeas in large warehouses in Niger. This study evaluated hermetic storage bags to manage both common and emerging insect pests. Treatments included (i) the Purdue Improved Crop Storage (PICS) hermetic bag; (ii) a woven polypropylene (PP) bag with a polyethylene (PE) liner and Phostoxin; and (iii) a woven PP bag without Phostoxin (control). Naturally infested cowpea grains were obtained from the Office des Produits Vivriers du Niger (OPVN) warehouse in Maradi, Niger. Infestation levels were assessed using 12 samples of 500 g each, randomly collected from each treatment at the start and end of the trial. Major pests identified were C. maculatus, T. granarium, and Tribolium sp., with initial populations of 0.83, 0.44, and 0.83 adults per 500 g of cowpea, respectively. After six months of storage, pest densities in the control increased significantly: 232-fold for C. maculatus, 7.4-fold for T. granarium, and 2.7-fold for Tribolium sp.; resulting in a 38.5% weight loss. In contrast, both the Phostoxin and the PICS hermetic bags effectively suppressed pest populations, preventing weight loss. This study confirms the efficacy of hermetic storage, such as the PICS bag, in protecting cowpeas from both common and emerging pests.

Millet (Pennisetum glaucum (L.) R. Br.) is the most widely consumed cereal in Niger. Although its production lasts six months, consumption is year-round, requiring effective and safe storage solutions. Post-harvest losses of millet can reach up to 17% after several months of storage. Chemical pesticides are commonly used in large warehouses, but concerns over misuse and health risks have driven interest in safer alternatives. This study assessed the effectiveness of traditional and improved storage methods in controlling Trogoderma granarium Everts, an emerging pest of millet in large warehouse facilities. Three storage methods were tested: (i) a hermetic Purdue Improved Crop Storage (PICS) bag; (ii) chemical pesticide Phostoxin; and (iii) an untreated ordinary polypropylene bag as a control. Naturally infested millet obtained from a large warehouse was assessed for each treatment at the start and end of a six-month storage period. Two insect pests were identified, T. granarium and Tribolium sp. Initial infestation levels were 60 larvae and 0.47 adults per 500 g. After six months, the control showed a 1.7-fold increase in T. granarium larvae, a 2.96-fold increase in its adults, and a 3.19-fold increase in Tribolium sp. adults, resulting in 19.15% weight loss. In contrast, PICS and Phostoxin treatments maintained initial pest levels with no weight loss. These results suggest that hermetic storage is a safe, effective, and chemical-free alternative for preserving millet in large warehouses.