The losses in wheat storage associated with infestation of S. zeamais and R. dominica were modeled. In the course of 90 days of storage, insect population, moisture content, percentage of weight loss of insect damaged grains, test weight per hectoliter and dry matter loss of wheat grains were evaluated at 16-36 °C. In conformity with the Brazilian Classification and Commercialization Standards, the designation "below standard"is applied to wheat that contains more than 1.5% of insect damaged grains and the models predict that in case of S. zeamais a population of 180 insects kg-1 would be necessary to achieve 1.5% of damaged grains, associated with a moisture content of 0.13%, test weight reduction of 0.4 kg hL-1 and 0.7% of dry matter loss. For R. dominica, 64 insects kg-1 would be necessary to achieve 1.5% damaged grains, associated with a moisture content of 0.07%, test weight reduction of 0.5 kg hL-1 and 0.5% of dry matter loss. For equal size populations, the R. dominica was more harmful than S. zeamais. Among loss, grade and class factors for wheat, percent weight loss of insect damaged grains was more affected by the insect population growth.
Sitophilus zeamais; Rhyzopertha dominica; stored wheat; losses; models
