Persistence and efficacy of enhanced diatomaceous earth formulations for eco-friendly management of four stored product insects

Laboratory study was carried out to investigate the residual efficacy of enhanced DE formulations against three stored grain beetle spp. and psocids on wheat. Quantities of wheat were treated with respective doses of DEs; samples were taken on the day of storage and every 30 days until completion of 120 days. Adults of each sp. were exposed to these samples at 28±2ºC and 65±5% RH, the mortality counts were taken after different exposure intervals. Mortality of psocids was higher followed by <em>Cryptolestes ferrugineus</em>, <em>Rhyzopertha dominica</em> and <em>Tribolium castaneum</em>. An increase in mortality was observed with a rise in DE dosage and exposure intervals; however, decrease in mortality was observed after 120 days of storage. The suppression of progeny production was remarkably high at the beginning of storage, however, after 60 days, the progeny started to increase with an increase in storage period. Enhanced DEs were very effective at considerably low dosage compared to the previous DEs and will contribute to resolve the issue of bulk density and lower the risk of health and environmental issues.