Evaluation of Plant Extracts as Sustainable Alternatives against the Saw-Toothed Grain Beetles (<i>Oryzaephilus surinamensis L.)</i> Infesting Stored Grains in Khairpur, Sindh, Pakistan

The saw-toothed grain beetle (Oryzaephilus surinamensis L.) is a common pest that causes problems by infesting stored grains, leading to considerable post-harvest losses in both the quantity and quality of grains. Although conventional chemical insecticides are effective, they pose serious threats to environmental health and human safety because of their residual toxicity and potential to induce resistance in target pests. In response to these concerns, the present study evaluated the efficacy of selected plant extracts, Neem (Azadirachta indica), garlic (Allium sativum), eucalyptus (Eucalyptus spp.), and peppermint (Mentha piperita), as sustainable alternatives for managing O. surinamensis infestations in stored wheat grains. Laboratory bioassays were conducted to assess contact toxicity, repellency, and feeding deterrence at varying concentrations (2%, 4%, and 6%) over different time intervals. The findings indicated that neem extract and eucalyptus extract had the greatest insecticidal effect that causing the greatest reduction in mortality of the beetles. Feeding damage to the beetles showed a great potential as insecticidal repellents. There was an intermediate level of activity of garlic and peppermint on all parameters. These results imply that botanical insecticides made using the native plants can also be enjoyed as eco-friendly and valuable methods of pest management in the grain stores. This research will be useful in developing the current understanding of the benefits of sustainable pest management practices and facilitating the use of plant-based bioactive compounds as a substitute for synthetic chemicals.