Behavioural response of Sitophilus zeamais to essential oil-derived compounds

Insect infestations in stored grain systems pose a significant threat to global food security by reducing both the quality and quantity of cereals. Sitophilus zeamais , the maize weevil, is one of the most destructive pests affecting stored cereals worldwide. While synthetic chemicals are commonly used for control, concerns regarding environmental safety, human health and the emergence of insecticide resistance have intensified the search for alternative control strategies. Essential oils and their constituents have emerged as promising eco-friendly alternatives. In this study, we evaluated the behavioural responses of S. zeamais to three isolated high-purity essential oil-derived compounds – 1,8-cineole, (S)-(−)-Limonene, and Eugenol – using a four-arm olfactometer. Adult S. zeamais were exposed to different concentrations of each compound, and repellence was inferred from the time spent in the central or distal zones of the olfactometer. The essential oil-derived compounds tested demonstrated promising repellent properties against weevils, as the insects spent more time away from the source or remained in the central region of the device, indicating repellent activity. Our findings contribute to the expanding body of research on botanical pest control methods and underscore the potential of these compounds to support the development of sustainable and environmentally friendly pest management strategies. These approaches can reduce dependency on synthetic chemicals while effectively limiting post-harvest losses in stored grains. • S. zeamais spent more time in olfactometer distant zones, confirming repellence of volatiles. • (S)-(−)-Limonene caused strong avoidance in S. zeamais. • No significant behavioural differences were found between males and females. • 1,8-cineole showed the weakest repellent effect among the compounds tested.