Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/15/2001
Publication Date: 6/22/2001
Citation: ARTHUR, F.H., THRONE, J.E., MAIER, D.E., MONTROSS, M.D. IMPACT OF AERATION ON MAIZE WEEVIL (COLEOPTERA: CURCULIONIDAE) POPULATIONS IN CORN STORED IN THE NORTHERN UNITED STATES: SIMULATION STUDIES. American Entomologist, Summer 2001. Interpretive Summary: Several traditional corn protectants could be eliminated through restrictions imposed by the Food Quality Protection Act (FQPA), and new methods must be developed to manage insect pests in stored corn. One possibility is the expanded use of controlled aeration using low-volume ambient air to cool stored corn to levels that will not support insect growth and development. We used historical weather data to classify the northern United States into different regions, and to predict population development of the maize weevil in aerated versus unaerated corn stored in each area. Aeration would have the greatest potential impact in the warmest regions within the northern United States; immediate aeration for timed intervals after harvest would reduce the temperature of the corn to levels that would not support maize weevil development, but in unaerated corn, it would take 2 or 3 months for temperatures to reach this level. Consequently, the predicted numbers of immatures and adults were far lower in aerated corn compared to unaerated corn. Proper use of aeration could reduce or even eliminate the need for insecticide applications on corn stored in the United States.
Technical Abstract: Historical weather data were used to divide the northern United States into 5 climatic zones based on the number of hours below 15.6 C (60 F) in a calendar year. A model for population growth and development of the maize weevil, Sitophilus zeamais Motschulsky, was integrated with a bin cooling model to predict the numbers of immatures and adults produced in unaerated and aerated corn during one year of storage. In all zones, aeration would immediately lower grain temperatures to about 15 C, while it took 2 or 3 months for the temperatures in unaerated corn to drop to this level. Populations of immatures in unaerated corn were predicted to increase during autumn, though numbers would decrease as the climatic zones progressed northward. In all zones, the number of immatures in unaerated corn would decline through winter and spring of the following year, and then increase beginning in mid-summer. In contrast, immature populations in naerated corn stored in all but the southernmost zones would decline during autumn, and in each zone the total number at the end of the calendar year would be about 2 orders of magnitude lower than in unaerated corn. Adult populations were not predicted to increase during autumn in unaerated corn, with the exception of corn stored in the southernmost zone. However, adult populations in all zones would begin to increase in August and September of the following year. Aeration would reduce the number of adults to about 1.5 to 2.0 orders of magnitude less than the numbers predicted for unaerated corn. Advancing the storage date by 1 or 2 weeks had little effect on predicted populations of immatures and adults in unaerated or aerated corn stored in the three northernmost zones. Aeration should provide adequate management of maize weevil in corn stored in the No. US.