Efficacy of amorphous silica dust for use against Sitophilus granarius and Rhyzopertha dominica as a grain protectant

Authors: QUELLHORST, HANNAH - Kansas State University; SAKKA, MARIA - University Of Thessaly; BALIOTA, GEORGIA - University Of Thessaly; ATHANASSIOU, CHRISTOS - University Of Thessaly; ZHU, KUN YAN - Kansas State University; Morrison Iii, William

Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/28/2025
Publication Date: 7/3/2025
Citation: Quellhorst, H.E., Sakka, M.K., Baliota, G.V., Athanassiou, C.G., Zhu, K., Morrison III, W.R. 2025. Efficacy of amorphous silica dust for use against Sitophilus granarius and Rhyzopertha dominica as a grain protectant. Journal of Stored Products Research. Volume 114, September 2025, 102747. https://doi.org/10.1016/j.jspr.2025.102747.
DOI: https://doi.org/10.1016/j.jspr.2025.102747

Interpretive Summary: With the rise of insecticide resistance in common stored product insects and fewer options for control, it is imperative to explore other options for pest management. One option is the use of inert dusts such as diatomaceous earth (DE) or amorphous silica dust, which can puncture insect cuticles and cause mortality. In this study, we investigated the utility of an amorphous silica dust originally formulated for use against bed bugs, and tested its ability to function as a grain protectant against two common stored product insects, the granary weevil and lesser grain borer. High mortality (>90%) for both insect species was achieved after exposure for 14 days on soft wheat treated with 500 and 1000 ppm silica dust. Progeny production after 65 days was nearly zero for lesser grain borer and granary weevil, at 500 and 1000 ppm silica dust treatments. At lower rates, 100 and 200 ppm, silica dust was more effective at reducing progeny in lesser grain borer than in granary weevil. Overall, we found that silica dust is an effective grain protectant on wheat against these two bulk storage pests and shows potential for development as a new product for use in an integrated pest management program after harvest.

Technical Abstract: With the rise of insecticide resistance in common stored product insects and fewer options for control due to increased regulatory oversight, it is imperative to explore other options for management. One option is the use of inert dusts such as diatomaceous earth (DE) or amorphous silica dust. In this study, we investigated the utility of an amorphous silica dust originally formulated for use against bed bugs, and applied it as a grain protectant for two stored products insects (Sitophilus granarius and Rhyzopertha doninica). Lots of wheat were conditioned with five concentrations of silica dust (ChinCheX Bed Bug Insecticide, 99% amorphous silica), including: 0 (control), 100, 200, 500, and 1000 ppm. Insects were exposed continuously with condition evaluations at 7 and 14 days. Adults were then removed and the grain was kept for 65 d to assess progeny production. Mortality was 90 and 100% for the 500 and 1000 ppm treatments for R. dominica and 100% for both 500 and 1000 ppm treatments for S. granarius. Progeny production was less than 2 insects at 200 ppm and zero at 500 and 1000 ppm for R. dominica, while for S. granarius, there was less than 1 insect at 500 ppm and zero at 1000 ppm. Overall, we found that silica dust is an effective grain protectant on wheat against these bulk storage pests and provides a valuable option for use in an integrated pest management program.