Used Five Inert Dusts to Control Two Insect Pests on Stored Rice Grains

Document Type : Original Article


1 Plant Protection Department, Faculty of Agriculture, Benha University, Egypt.

2 Stored products insects, Plant Protection Research Institute (PPRI), Agric. Res. Center (ARC), Egypt.


Rice grains are often infested by Sitophilus oryzae and Corcyra cephalonica, causing quality and quantity losses. In this study, the insecticidal effects of inert dust (diatomaceous earth(DE), calcium carbonate, kaolin(KA), rock phosphate and silica gel) on S. oryzae adults and C. cephalonica larvae were assayed. Four concentrations of each inert dust were tested at 2,3,4and5% on rice grains. Results indicated that diatomaceous earth and phosphate rock 5% lead to the highest insecticidal action with adult mortality of 98.3and96.6% for S. oryzae adults, 15 days post-treatment, respectively. As well, diatomaceous earth and phosphate rock 5% lead to the highest insecticidal action with larval mortality of 100.0%for C. cephalonica larvae after 7 days. On the contrary, treatment with 5%silica gel recorded the lowest toxicity to S. oryzae adults (65.66%) after 15 days of exposure. While calcium carbonate 5% resulted from the lowest toxicity C. cephalonica larvae(61.2%)after 7-day exposure. According to the obtained results, the highest reduction in the progeny of S. oryzae adults was registered in treatments with diatomaceous earth(5%)and kaolin(5%), being 91.4and91.3%, respectively. As for the highest reductions in the progeny of C. cephalonica larvae, in treatments with diatomaceous earth(5%)and phosphate rock(5%), those were 97.4and 97.2%, respectively. All treatments with inert dust caused a reduction of weight loss and damage of rice grains 60 days post-treatment in comparison with untreated grains. Results showed that all the tested inert dusts treatments except silica gel increased germination percentages of seeds than the control. The obtained results indicated that inert dusts may be considered, safe and available in the local environment, so, they are used as alternatives to insecticides for the control of S. oryzae and C. cephalonica infestations to stored rice grains.