If grain will be stored on the farm, one goal should be to keep it relatively insect-free, preferably without using insecticides or fumigants.
Taking steps to prevent a buildup of insect numbers requires time and planning, but the outcome is grain that is not infested with insects and will not be docked.
The following insect-management tactics should be considered for preventing infestations of insects in stored grains. If successful management is achieved with these tactics, fumigation of grain can be avoided.
- Sanitation (cleanup of old grain and grain debris)
- Empty-bin spray with an insecticide
- Empty-bin fumigation, primarily to control insects in the subfloor plenum
- Storing clean, dry grain
- Treating grain with a protectant insecticide
- Aeration to cool the grain to prevent insect feeding and reproduction
- Regular measurement of grain temperature and sampling for insects
If fall-harvested crops (corn, soybean, and grain sorghum) are to be removed from storage by May or June the year after harvest, the nonchemical tactics listed above should be adequate to prevent infestation by stored-grain insects. Empty-bin sprays, empty-bin fumigation, and protectant insecticides probably will not be necessary.
Because wheat is harvested in midsummer, when warm temperatures enable insects to develop and reproduce rapidly, it is more vulnerable to insect infestation. However, if wheat will not be stored for more than one month, the probability for a significant buildup of stored-grain insects is relatively low, so nonchemical management tactics should be sufficient.
All grains stored long term probably will become infested with stored-grain insects. However, implementing an insect-prevention program using the tactics previously listed should lower the probability and intensity of infestation.
If an insect infestation develops and fumigation becomes necessary, we recommend employing a professional fumigator. The legal and safety requirements for fumigating stored grain make the expense and risk more than most farmers are prepared to accept.
Using Insecticides and Fumigants:
The USEPA has designated certain pesticides for “restricted” use. The fumigants aluminum phosphide (alone or in combination with carbon dioxide), sulfuryl fluoride, and chloropicrin are restricted use pesticides.
Commercial applicators must be certified to apply restricted use pesticides. Elevator employees responsible for grain treatment at their place of employment must be certified under the category Grain Facility Pest Control Applicator.
Commercial fumigation professionals who treat stored grain or grain products at farms, elevators, or warehouses must be certified by the Illinois Department of Public Health.
A private applicator who wishes to purchase or apply restricted use pesticides “for the purpose of protecting any agricultural commodity on property owned or rented by him or as exchange labor (no compensation) on the property of another” must obtain certification by passing an examination administered by the Illinois Department of Agriculture.
Regulations enacted by the Illinois Department of Agriculture mandate that private applicators must obtain special certification to purchase and apply grain fumigants.
To obtain certification for fumigant application, individuals must first pass the private applicator exam and then pass a grain storage and fumigation exam. For information about training materials, Persons who apply pesticides should be aware that the applicator is always responsible for the results of pesticide applications.
To avoid accidents and maximize the effectiveness of any application, always read the pesticide label and follow all directions and safety precautions. Be sure that the pesticide is specifically labeled for the pest, site, and application method planned. The label is the law.
Insects Attacking Stored Grain:
Several types of insects inhabit stored grain. Identification is often difficult because most stored grain pests are small (1?16 to 1?4 inch long), and many species are similar in appearance. Information about identifying the many species of stored-grain insects is not presented here; see instead the reference list at the end of this chapter.
It is important, however, to recognize the different groups of insects that live in stored grains because management considerations may differ according to the insects’ characteristics and behavior. Different species vary significantly in their potential to cause economic damage, and some insects cause no damage to stored grain.
Authors:
Rick Weinzierl : Department of Crop Sciences
Russell Higgins : Matteson Extension Center
