Location: Stored Product Insect Research Unit
Title: Using a population growth model to simulate response of Plodia interpunctella Hübner populations to timing and frequency of insecticide treatments Authors
Submitted to: Journal of Pest Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 22, 2012
Publication Date: May 15, 2012
Citation: Fontenot, E.A., Arthur, F.H., Nechols, J.R., Throne, J.E. 2012. Using a population growth model to simulate response of Plodia interpunctella Hübner populations to timing and frequency of insecticide treatments. Journal of Pest Science. 85(4): 469-476. Interpretive Summary: Insecticides are used to suppress populations of insects in stored commodities, but it is difficult to determine long-term impact of different insecticide application strategies on insect population growth. We developed a computer model that simulates population growth of the Indianmeal moth, a major pest of stored grains and dried fruits, and we used the model to simulate the impact of timing and frequency of applications of different types of insecticides on long-term growth of Indianmeal moth populations. The most effective strategy tested for controlling Indianmeal moth populations was the use of biweekly applications of insecticide. The results will help pest managers in the food industry make sound management decisions.
Technical Abstract: Management strategies for urban and stored-product pests are chosen for a variety of attributes including cost, efficacy and human safety. Low-risk alternatives to traditional neurotoxic insecticides, such as insect growth regulators, may be valuable management options. However, as these products become available there is a need to determine efficacy in regard to survival after exposure, timing of application, and effect on population dynamics, so that overall value of these treatment methods can be determined. This study was conducted to predict the effect of methoprene and two conventional insecticides combined with methoprene on development of Plodia interpunctella Hübner populations on wheat diet and raisins. Effects on populations were simulated using a modified temperature-based growth model at 24, 30, and 35°C, and the effects of timing and frequency of insecticide treatments were determined. The results of this study indicate that frequency is more important than timing of insecticide applications in the management of this pest. This study also demonstrated that P. interpunctella populations grow so rapidly that numerous sequential insecticide treatments may be needed to reduce populations, even at temperatures and on diets that are not optimal for P. interpunctella development.