The evaluation of the mortality and repellency effect of diatomaceous Earth (Sayan®) on three coleopteran store pests

Abstract

Replacing common insecticides with natural compounds can be a suitable method for controlling damage to stored products by pests. In this research, the mortality and the repellency effect of Sayan® formulation of Diatomaceous Earth on adult Sitophilus oryzae L., Oryzaephilus surinamensi, and Tribolium castaneum (Herbst) have been investigated. A petri dish with an 8 cm diameter and a height of 1.5 cm was used for the bioassay. The mortality assessment was dose and time dependent. The LC50 values were 2.5, 1.9 and 12 gr/kg food for S. oryzae L., O. surinamensi and T. castaneum, respectively, at 96 h post-treatments. Consequently, O. surinamensi and T. castaneum had the highest and the least sensitivity to this compound, respectively. The maximum mean of the repellency effect of Diatomaceous Earth on S. oryzae L was 48.95%. Overall, the results of this research have shown that Diatomaceous Earth can be used against stored products pests and it presents an alternative way for the chemical control of these pests.