Dryacide treatment of stored wheat: its efficacy against insects, and after processing

Abstract

The efficacy of Dryacide (diatomaceous earth coated with silica aerogels) on wheat was tested in the laboratory against adult and immature stages of 4 species of Coleoptera and against immature stages of 1 species of Lepidoptera. The minimum effective level of Dryacide increased in the following order: immature Ephestia cautella (Walker) ~ immature Tribolium castaneum (Herbst) < immature Rhyzopertha dominica (F) < adult R. dominica ~ adult T. castaneum < adult Sitophilus oryzae (L) < adult Sitophilus granarius (L) < immature Sitophilus species. When wheat treated with Dryacide was milled in the laboratory without prior cleaning, less than 3% of the Dryacide carried over into the flour. Commercial cleaning of wheat removed (�s.e.) about 98 � 1% of Dryacide, and no Dryacide could be detected in the flour. Dryacide treatment did not affect flour quality as determined by the volume of sponge cakes and the production of carbon dioxide by fermenting dough.