By Dr. Cisse Spragins, Founder & CEO
Stored product pests can be annoyingly persistent in certain accounts, such as grain storage and processing facilities, food and pet food warehouses, and retail stores. Pet stores and residences can also have persistent problems. While large facilities such as grain storage and processing plants are often monitored and fumigated, fumigation isn’t usually practical in food warehouse and distribution centers, or in retail stores or residences.
When using pheromones for monitoring for pests like Indianmeal moths (IMM), it is important to remember than the Plodia and Ephestia pheromones are very potent. They should not be used except in large facilities, and should be positioned ideally 50 ft. from the nearest door. If placed any closer, they can effectively draw insects in from outside if the weather is sufficiently warm.
Pheromone-containing gels, which may also contain some food attractants, are now available in syringes. This allows smaller doses to be used, which can moderate the effect somewhat. (Note that beetle pheromones typically have a shorter range, so this issue is less of a problem.) Such products often contain a blend of several pheromones, so they are an economical option. They can be applied to a glueboard of whatever size best fits the application.
For retail stores, low-profile, tamper-resistant, “smush-proof” monitors are ideal for putting in and under shelving units for monitoring — particularly around pet food. While removing the infested commodity is the most important step, several other options are available and may be needed in addition.
One low-impact and highly effective control option that is suitable for certain areas, which perhaps is not often thought of, is engineered amorphous silica gel. The dust can be puffed into voids and cracks, and can also be mixed with water and spot-sprayed onto surfaces. It will leave a white mark when dry, so treatment should be in areas that aren’t readily visible. It will be effective for pretty much any crawling insect or arthropod, provided the treatment area remains relatively dry, and it offers a long residual.
Other control options include esfenvalerate in a low volatile organic compound (VOC) formula that can be sprayed or fogged. Incorporating an insect growth regulator (IGR) will provide additional benefits.
Often, the biggest challenge is finding the source. It is important to consider unconventional sources, such as old rodent bait, grains and nest material that may be harbored by rodents — or even dead animals, birds or droppings in certain cases. If it is not possible to remove such sources from wall voids or other hard-to-reach areas, amorphous silica is likely the best option for treating the void, because of its long residual.