Efficacy of Anacardium occidentale, Citrus sinensis, and Croton zambesicus as Natural Maize Seed Protectants against Maize Weevil, Sitophilus zeamais (Motschulsky) [Coleoptera: Curculionidae]

Background and Objective: Maize (Zea mays) is a primary cereal crop across West Africa, particularly Nigeria. Despite its high production, maize weevil (Sitophilus zeamais) infestation threatens both field and storage integrity. Conventional chemical insecticides, while widely used, pose environmental hazards, health risks, and mammalian toxicity. This study evaluated the insecticidal potential of three botanical species (Anacardium occidentale, Croton zambesicus, and Citrus sinensis) as natural maize seed protectants against S. zeamais during storage. Materials and Methods: Botanical powders were applied at 0.2-1.0 /20 g of maize, and extracts at 0.2-1.0 mL/20 g. Parameters measured included adult mortality, emergence inhibition, grain weight reduction, damage percentages, and weevil perforation index (WPI). All statistical analyses were performed at a 5% level of significance (p<0.05). Statistical analysis was carried out using IBM SPSS Statistics. Results: After 48 hrs, C. sinensis powder caused the highest adult mortality (66.66%), followed by A. occidentale(46.66%) and C. zambesicus (40%). Extracts were more toxic than powders, with A. occidentale extract achieving 80% mortality within 24 hrs, C. sinensis 70%, and C. zambesicus 53.5%. All extracts completely suppressed oviposition, prevented adult emergence, and significantly reduced weight loss and seed deterioration. Conclusion: These botanical materials effectively controlled S. zeamais, offering safe, economically viable alternatives for stored maize protection. Their integration into Integrated Pest Management (IPM) strategies can reduce grain losses, ensure seed viability, and enhance food security in maize-dependent regions.