Earlier this summer, and as recently as last week, I received inquiries from different counties in Kentucky on the control of insects (i.e., rice weevil, lesser grain borer weevil, and Indian meal moth) in stored grains. Now that corn fields are turning yellow, grains are drying, and the harvest season is around the corner for corn, as well as for soybeans (a little later), producers need to be prepared, and bins need to ready. To reduce grain damage, storage units should have unfavorable conditions for the survival of insects or molds that affect grains or lower their quality.
Many insect pests in stored grain are entirely different from those seen by producers and crop consultants during the growing season. Most importantly; the management, tools, techniques, and equipment needed to prevent insect infestations in stored grain are different from those used in the field.
Briefly, essential conditions that prevent any insect activity in stored grains include keeping bins clean inside and out as soon as they are empty, sealing any gaps or holes in the sides of the bins using caulk or polyurethane foam, spraying a 3-foot swath on the outside walls of the bin, and 6 to 10 feet of the surrounding concrete and sod.
Drs. Doug Johnson and Sam McNeill developed a 16-point list for controlling insects in stored wheat that provides organized and efficient steps to avoid the development of insects in grain. These steps can be applied to corn as well and are presented below (Table 1).
This updated table provides additional resources for the management of insects in stored grains.
See the following UK publications for more information on topics treated in this publication:
- Aeration, Inspection and Sampling of Grain in Storage Bins (AEN-45):
- Controlling Insects in Stored Grain (ENTFACT-145)
- Fumigation Training Manual (link)
- Products for Control of Insect Pests in Stored Field Corn Grain (ENT-16)
- Products for Control of Insect Pests in Stored Small Grain (ENT-47)
- Products for Control of Insect Pests in Stored Soybeans (ENT-13):
- Suffocation Hazards in Grain Bins (AEN-39)
By Raul Villanueva, Extension Entomologist