Treatment of rice with diatomaceous earth and effects on the mortality of the Red flour beetle Tribolium castaneum (Herbst)

Diatomaceous earth has been demonstrated in Australia, Germany and the USA to protect stored products from infestation by insect pests. However, appli cation of diatomaceous earth has rarely been used in Asian countries for th e protection of stored grain from insect damage. These facts and the paucit y of existing data from the tropics prompted the present study of storage w ith diatomaceous earth. We exposed rice treated with the diatomaceous earth product Fossil Shield(R) to infestation by Tribolium castaneum Herbst, Dur ing the dry season, when tests were conducted, the mean temperature was 29/-2 degreesC and relative humidity was 80+/-3 %. The population of T. casta neum in rice was significantly reduced after treatment with Fossil Shield(R ). Diatomaceous earth at 1 g and 2 g per kilogram rice reduced population g rowth of T. castaneum to a coefficient of 0.27, and 0.02 respectively after 42 days. Fossil Shield(R) at 0.5 g per kilogram rice increased the mortali ty of T. castaneum, but did not stop population growth.