A comparison of the effect of two diatomaceous earth formulations on <i>Plodia interpunctella</i> (Hübner) and the effect of different commodities on diatomaceous earth efficacy

  • B. Timlick Canadian Grain Commission, 844 – 303 Main St. Winnipeg, Manitoba, Canada, R3C 3G8. Email: blaine.timlick@grainscanada.gc.ca
  • P. G. Fields Cereal Research Centre, Agriculture and Agri-Food Canada, 195 Dafoe Road, Winnipeg, Manitoba, Canada, R3T 2M9.


The efficacy of two diatomaceous earth formulations was tested on five commodities; maize, wheat, birdseed, sunflower and barley, against Plodia interpunctella (Lepidoptera: Pyralidae). Exposure to DE began at either the egg stage or 3rd instar stage and the reduction in emergence to adult was noted. There was no significant difference between the freshwater and marine (Protect-It) DE. When eggs were placed on treated diet, the LD90 was 135, 143 and 805 ppm for maize, wheat and birdseed, respectively. When 3rd instars were placed on diet, LD90 was 382, 444, and 1156 ppm for maize, sunflower and birdseed respectively.

Keywords: DE, Wheat, Maize, Birdseed, Sunflower, Indian meal moth
Section: Residual Insecticides - Synthetic and Botanical