Winter is not typically considered a high pest activity season, as outdoor pests are generally more active during the warmer months. However, for some parts of the country, winter pest control can be a difficult task. In addition to the normal pest pressure of a food processing or storage facility, these facilities will have outdoor pests seeking warm shelter when the weather turns cooler. So, to maintain an integrated pest management (IPM) program, adjustments need to be made based on factors such as neighboring businesses, elevation, and local climate. Following are some principles to follow to ensure your facility is “winterized.”
MAKING IPM ADJUSTMENTS
With fall being a traditional time for farmers to harvest crops in many areas, the activity can disrupt the feeding and shelter of field mice, insects, and other pests, and cause an increased pressure on any nearby food facility, which will extend into winter if steps are not taken. One step which can be helpful is increasing the frequency at which exterior bait stations and internal traps are checked to offset the elevated pest pressure. Once it is determined that populations have decreased, the frequency of checking of traps and bait stations can return to normal.
Some facilities choose to stop checking exterior bait stations during the colder months altogether, particularly those stations that become inaccessible due to snow. Ironically, unchecked bait stations may become shelters for mice during the winter months. Snowfall does not necessarily mean rodent activity will decrease. In fact, snow can act as an insulated blanket, and can keep mice warm in nearby fields. Thus, the risk to each facility will need to be evaluated on a case-by-case basis.
There are also some facilities that turn off their insect light traps during the winter months. But stored pest monitoring devices, such as pheromone traps, should always remain in effect. Additionally, regular inspections of insect-susceptible materials, such as flour and grains, should be conducted on a regular basis no matter the season. Thus, all such activities should remain in effect even though the storage areas may get cooler.
One of the most effective methods for deterring pest activity is maintaining a fully sealed building. It is a good practice to keep all doors closed whenever possible. Sometimes this requires educating employees on the importance of keeping the doors closed. Even leaving a door open for a two-minute smoke break can be an opportunity for pest ingress.
All other small holes and gaps also should be sealed. If outdoor insects such as worms or centipedes are found at the wall/floor juncture or near support beams, this may indicate that there are small cracks or openings in the floor. Check the floors and walls for moisture and small holes — and seal these areas as they are identified.
In addition to assuring all doors are closed and gaps sealed, you should check the exterior of the facility for harborage areas. Not all holes in exterior walls will penetrate the building; however, these holes could provide spaces where pests find harborage. These areas should be repaired as well.
Checking the exterior of the building and making necessary repairs in preparation for winter is certainly easier in the warmer months — particularly in areas where the ground turns hard due to frost. However, if this was not done in the fall, it is advisable to do an exterior inspection and make repairs as soon as possible.
Some buildings have “heaving” issues during the winter months. This is due to moisture in the ground freezing and expanding. This can warp doors and door frames, create cracks in the floor, and cause damage to walls. It’s important to assure these issues are addressed as soon as possible. Monthly self-inspections should identify these issues as they occur, and potential ingress points should be sealed when they are identified.
Moisture and frost in the winter months also can compromise the integrity of the roof. Damage to the roof and other structures, such as bucket elevator legs, can cause leaks into production and storage areas. Additionally, over time, pest ingress points could develop. Make sure all bucket elevator legs have no holes or gaps and are fully sealed. Some roofing materials are better than others, and when food safety is a concern, adequate resources must be allocated to assure roof integrity is maintained.
Neglected outbuildings and storage trailers can shelter pests as well. Even when these are located a short distance from the food facility or entrance; there are some pests that are very opportunistic and will seek out and enter open doors whenever possible. Make sure all out-buildings and other structures are inspected on a regular basis — no less than monthly.
Editor’s note: This story is the first part of a two-part series called “Winterizing" Your Pest Control Efforts. Read part 2 here.