Prediction of insect populations in grain storage

Data on population growth rates for four insect species were used to develo p prediction models of populations in grain stores. The form of the model w as based on an existing insect model from the literature. The species chose n (Rhyzopertha dominica, Sitophilus oryzae, Oryzaephilus surinamensis and T ribolium castaneum) represent common Australian grain storage pests. The re sulting models were incorporated into a one-dimensional drying and aeration simulation program, and plots of predicted populations at different levels during drying and aeration were obtained. The model was found to predict g rowth rates under tropical conditions in good agreement with laboratory dat a. Agreement was poorest at low temperatures and for Sitophilus oryzae only , at low relative humidities. The model consistently explained about 95% of the variance in the data for each species. Psychrometric plots of the data and model are presented. (C) 2000 Elsevier Science Ltd. All rights reserve d.