Effectiveness of nano dust enhanced with pirimiphos-methyl in controlling Sitophilus oryzae on wheat grain

Abstract

The bioefficacy of several inert materials, such as Diatomaceous earth (DE), bentonite, and biochar enhanced with pirimiphos-methyl against Sitophilus oryzae, was used to evaluate the insecticidal activity of three new formulations using the technique of mixing with grain. DE was the most effective material (LC50 3.198 g/kg), followed by biochar LC50 3.709 g/kg, whereas bentonite was the least effective (LC50 3. 979 g/kg). The three materials were loaded with pirimiphos-methyl (0.5%). The formula of Pirimiphos-methyl with DE reported the highest significant effect compared to the other two formulations, with an LC50 value of 0.082 g/kg. DE formula had a co-toxicity coefficient value that was 6.46 times greater than pirimiphos-methyl, followed by the biochar formula, which was 1.74 times more effective, and the bentonite formula, which had a 0.69-fold increase in activity. In the laboratory examination of the wheat’s free and compact bulk densities after being treated with LC50s of each dust material, DE slightly affected wheat-free bulk density. Still, both bentonite and biochar reduced the free bulk density. However, all the tested materials decreased in compact bulk density. The germination percentages of wheat treated with LC50 values of DE and bentonite and biochar after 10 days of storage revealed no significant difference between treated and untreated seeds after 7 days of germination.