Post-Harvest Protection Strategies: Comparing Diatomaceous Earth and Spinetoram Against Key Storage Pests

Stored grain pests significantly threaten food security by causing both quantitative and qualitative losses during post-harvest storage. This study evaluated the insecticidal efficacy of diatomaceous earth (DE) and spinetoram (SPM) against Trogoderma granarium Everts (Coleoptera: Dermestidae), Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), Sitophilus oryzae Linnaeus (Coleoptera: Curculionidae), and Rhyzopertha dominica Fabricius (Coleoptera: Bostrichidae), on wheat and rice grains under laboratory conditions. Treatments were applied at varying concentrations, and insect mortality was assessed at 1, 2, 7, 14, and 21 days, and progeny suppression was evaluated after 65 days of treatments application. Results revealed that spinetoram, particularly T7 (2.0 ppm), induced rapid and complete mortality (up to 100%) across all species and effectively suppressed progeny emergence. In contrast, DE, though slower in action, still achieved significant efficacy at T4 (300 ppm), reaching up to 86.67% mortality of T. granarium in treated wheat samples and caused substantial reductions in progeny production. Comparative analysis highlights spinetoram’s superior performance in short-term pest suppression, while DE offeres a slow but more sustainable and environment-friendly pest management option. These findings not only highlight the potential of integrating chemical and non-chemical methods to manage stored grain insect pests but also offer valuable information regarding the selection and application of effective stored grain pest management approaches.