EFFECTIVENESS OF NEEM SEED EXTRACTS IN THE FIGHT AGAINST WEEVILS OF MAIZE IN STORAGE FOR SUSTAINABLE EATING PRACTICES

The invasion of maize pests (Sitophilus zea mays Motschulsky) in crops and storage areas causes enormous losses. To overcome this constraint, producers and owners of storage warehouses generally use synthetic insecticides. These are polluting, expensive and have harmful effects on the health of consumers and the environment. In the search for alternatives for healthy and sustainable eating practices, the objectives of this work were to evaluate the repellent capacity of Azadirachta indica seed oil extract on corn weevils in storage, its efficacy on maize weevils in storage, and the contact efficacy of seed powder extracts on maize weevils in storage. Methods: Phytochemical screening was carried out on the extracts obtained according to some known procedures. The effectiveness of Neem extracts was determined by repellency; contact toxicity tests were carried out according to the usual methods. Results: Phytochemical screening shows secondary metabolites such as terpenes, flavonoids, phenols, alkaloids, tannins, Anthraquinones, coumarins, Anthocyanins, terpenes, among which you can find the actives principles of A. indica, responsible of the insecticide activity of Neem extracts. Neem oil is repellent at 62.5 %. This allows us to categorize it in the class IV of repulsive substances. However, it’s moderately repellent during the first two hours and repellent after two hours. This oil was lethal against Sitophilus Zea mays, with 100 % mortality by contact at a dose of 400 µl, and a nearby result at 200 µl. Neem powder caused 100 % mortality from the third day, after the treatment at most of doses (LC50 = 94,62 µl, LC50 = 1,07 g in 24h). Conclusion: Our Neem extracts protect the production against weevils and avoids losses, ensuring food security.