Unveiling the hidden threats: Diversity and ecological insights of stored-grain insect pests in Morigaon district, Assam, India

Post-harvest losses caused by insect infestations remain a significant challenge in tropical regions, particularly in areas where traditional grain storage methods are employed. The present investigation assessed the composition and diversity of insect pests associated with stored grains in six villages of Morigaon District, Assam, during the period from December 2024 to April 2025. A total of 60 grain samples, encompassing cereals, pulses, and other commodities, were examined. Morphological analysis identified 11 insect species belonging to 8 families, with Sitophilus oryzae, Tribolium castaneum, Rhyzopertha dominica, and Callosobruchus chinensis emerging as dominant pests. Diversity assessments using Shannon-Wiener, Pielou’s evenness, and Margalef’s richness indices revealed significant variation among villages and commodity types, with the greatest diversity observed in Singimari and Baralimari. Pest distribution was influenced by storage environment, crop type, and seasonal conditions, with paddy and pulses exhibiting the highest susceptibility. The study provides novel baseline information on stored grain pest diversity in North-East India and emphasizes the need for location-specific integrated pest management strategies to minimize storage losses and enhance regional food security.