This study was conducted to determine the effects of neem (Azadirachta indica A. Juss) and moringa (Moringa oleifera) seed oils on the storability of cowpea grain. Cowpea samples were treated with various concentrations (0.5, 1.0, and 1.5 mL/200 g cowpea) of pure neem and moringa oils and their mixtures in ratios of 1:1, 1:2, and 1:3. The treated cowpea samples were stored for 180 days. Data were collected every 30 days on number of eggs laid, total weevil population, and percentage of uninfested grains and analysed statistically. Significantly different means were compared using LSD at . Increasing oil concentration resulted in better cowpea protection, for example, in oviposition where the control had 6513 eggs, only 8 eggs were recorded in pure neem oil-treated sample at 0.5 mL/200 g. Generally, better results were obtained with higher oil concentrations either in their pure forms or mixtures. The control had a total weevil population of 4988, while most treated samples had none. The control samples had 0% uninfested grains, while 73–94% of uninfested grains were observed in treated samples after 6 months of storage. Therefore, mixture of the oils at 1.5 mL/200 g can be effectively used to store cowpea. 1. Introduction Cowpea (Vigna unguiculata (L.) Walp), one of the grains that suffer postharvest losses most, is a warm season, annual, herbaceous legume. It suffers heavily from insects, both in the field and when grains are stored after harvest. Yield reductions caused by insects can reach as high as 95%, depending on location, year, and cultivar [1]. The main pests during the growing season are the aphids while the main storage pests are the bruchids. The primary insect causing losses to stored cowpeas in West Africa is the cowpea weevil, Callosobruchus maculatus. Infestation begins in the field at low level. After the crop is placed in storage, the insect population continues to grow until the cowpea is completely damaged [2]. Another bruchid pest of cowpea is Bruchidius atrolineatus. This insect causes losses primarily around harvest times and does not reproduce in storage [3]. A single female weevil can reproduce herself 20-fold every 3-4 weeks. Harvested cowpea grains with a very light infestation will have a heavy infestation within 2-3 months [1]. Although insecticides are widely available, they require expensive equipment and training for their use. They are expensive, polluting, and potentially dangerous to users. Consequently, many cowpea growers in Africa do not use insecticides because they cannot obtain them; they cannot afford them;
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