2002 Annual Report
Research
Maintaining Grain Quality During Drying and Storage
William Wilcke, Professor
Nalladurai Kaliyan, Graduate Student
Vance Morey, Professor
Colleen Cannon, Assistant Professor, Entomology
Mario Carrillo, Graduate Student, Entomology
Funding Sources
Minnesota Agricultural Experiment Station; Anderson Research Fund
Objective
The overall purpose of our research is to reduce use of chemical insecticides
for managing insects (specifically Indian meal moth) in stored grain.
Project Description
Alternatives to chemical insecticides are needed for managing stored
grain insects. Insects have become resistant to some traditional stored
grain chemical insecticides and there is growing concern about the impact
of insecticides on the environment and on human health. It is well known
that insect activity slows as temperature decreases. Most insects become
dormant below certain critical temperatures and many insects die if held
at a low enough temperature for a long enough time. In the northern parts
of the U.S. grain growing areas, it should be possible to manage stored
grain insect populations by using aeration with outdoor air to control
temperatures inside bins of stored grain at levels that limit insect activity
and possibly even kill insects. More information is needed on the specific
time-temperature relationships needed to kill insects and on the typical
number of hours available at various outdoor temperatures in order to
develop recommendations that can be used to limit stored grain insect
populations and reduce the need for chemical insecticides.
Results
Accomplishments and results for 2002 include:
- Collected samples of Indian meal moth from several sites in Minnesota and several locations in other parts of the U.S.
- Developed a technique for measuring the supercooling point for individual insects. The technique involves use of a thermocouple attached to the insect body, a low-temperature freezer, and an insulated cube designed to produce the desired cooling rate.
- Determined supercooling points for a number of individual Indian meal moths from several different colonies and at several different life stages.
- Analyzed 35 years of weather data from the north central U.S. to determine the average number of hours when the outdoor temperature is likely to be below certain specific temperatures at various times of the year.
- Started development of computer models that will integrate prediction of temperatures in stored grain and in the bin headspace with prediction of Indian meal moth population.