The granary weevil is notorious for causing huge economic losses during storage in various parts of the world. The repeated use of chemical insecticides leads to contamination of seeds with toxic residues, which poses serious concerns to man. The present research work was carried out to find out the non-chemical control tactics for the management of granary weevils using diatomaceous earth under controlled laboratory conditions. The data were recorded on lethal, sub-lethal and repellent impacts of diatomaceous earth against the tested insect pests. The diatomaceous earth was used at fixed doses of 200, 300, 400, 500 and 600 ppm per 50 grams of grains, respectively. Results indicated an inversely proportional trend between different doses of diatomaceous earth and survival rate of the weevils i.e., by increasing the dose, the rate of survival decreased and maximum mortality was observed at the highest dose of DE at 21 days after the application of chickpea grains. A gradual increase in the mortality of weevils was observed by increasing the exposure to DE treated grains. The rate of repellency also increased by increasing the dose and exposure duration. The maximum mean percent repellency of 82.5% was observed after 72 h exposure period. The same trend was observed in case of F₁ adult emergence, emergence of weevil adults, infestation, weight loss, and adult life span. A decrease in F₁ progeny emergence was observed by increasing the dose rates of DE. The minimum progeny emergence, infestation and weight loss was observed in chickpea grains treated with maximum dose of diatomaceous earth. This indicates that the effectiveness of diatomaceous Earth was greatly affected by the selected doses of DE as well as exposure time against S. granarius. Cogent findings of the study were that at the dose of 600 ppm, reduction in progeny emergence of S. granarius can be achieved while increasing the dose rate can help in inhibiting the infestation. Hence suggested that diatomaceous earth can be used for the safer management of granary weevil.

Keywords: stored grains, diatomaceous earth, lethal effects, sub-lethal effects, repellent effects