Sanitation is Your First and Best Defence

On Farm Grain Storage

Farm-stored grain may become infested in two major ways. Infestations by insects such as the rice weevil and angoumois grain moth may develop in the field prior to harvest, especially in the southern United States. Infested grain is then brought to the storage bin and the insect population can continue to increase during the holding period. However, infestations are most likely to develop from small populations of grain insects that remain in or around improperly cleaned bins and grain handling machinery. Spilled grain or residues in harvest machinery or grain stored at animal feeding areas can also serve as important sources of insect pest problems. Obviously, it is very important to detect and eliminate potential pest reservoirs if on-farm stored grain infestations are to be reduced.

The Bin

Bin Preparation-Prebinning sanitation and bin preparation is absolutely essential. Thorough sanitation of bins removes most existing insect infestations. Cracks, crevices and other potential insect harborage areas should be mechanically eliminated where possible. Insecticides applied to bin walls, floors and, when applicable, to bin subfloor areas will help provide control of insects missed in bin cleanup. However, these insecticides will NOT cover for a poorly cleaned bin.

Follow these links to find insecticides that can be used to treat empty bins.

Never store new grain with old grain.

Preventive Maintenance- Grain bins and other grain storage facilities have numerous cracks and crevices and other harborage areas where insect pests can hide and develop. Thorough bin sanitation is necessary to clean up these areas, but the most permanent solution is to fill these areas with caulking material. Roof leaks or large holes in the walls or floor of the bin provide potential entry points for moisture as well as rodent and insect pests. Prompt repair of this damage is required to maintain a high quality grain storage environment. Long-term grain storage is possible. However, the success of a long-term grain storage program is related directly to the level of management applied to maintain an appropriate grain storage environment.

Near the Bin

The area immediately surrounding the bin should be kept clean. Be sure to remove and destroy all spilled grain. Control weeds and grasses, since they can harbor insect and rodent pests. Inspect outside walls and especially the base and roof for damaged areas that could allow pests and moisture to enter. Do not use the area immediately surrounding the grain bins to store cattle feed; keep stock feeders as far away as possible.


Grain handling equipment should be kept clean, also. Cleaning storage bins is of little value if you fill them using contaminated equipment. Combines, trucks, augers and grain driers should be thoroughly cleaned of all old grain

The Grain

The physical condition of the grain plays an extremely important role in long-term storage. Insects require both moisture and warmth in order to feed and reproduce. Although these requirements will vary by species, grain moisture above 12 percent and temperature between 60 and 90F will allow normal growth and reproduction. In general, grain stored under conditions which maintain high quality will be less susceptible to insect infestation.