Use of diatomaceous earth for the management of stored-product pests

Diatomaceous earth (DE) is almost pure amorphous silicon dioxide, made up of fossilised diatoms; it acts as an insecticide by absorption of epicuticular lipids and fatty acids, leading to desiccation in arthropods. Numerous DE formulations have been attempted for the management of stored-product pests with good results. DE is persistent in its action, poses few or no pest resistance problems, and it leaves no residue. The efficacy of DE is affected by factors such as: its provenance, temperature, humidity and characteristics of target pests and substrate. Application of DE at currently recommended doses causes changes in bulk density of the grain; however, the use of enhanced DE formulations provides control at much lower doses. Therefore, new formulations of DEs usually include other low toxicity insecticides.