Harvesting Results

So it is said that if you know your enemies and know yourself, you will fight without danger in battles.
If you only know yourself, but not your opponent, you may win or may lose.
If you know neither yourself nor your enemy, you will always endanger yourself.
— The Art of War, Sun Tzu (sixth century B.C.)

Even today, Sun Tzu’s ancient collection of writings about war can be applied in a business setting, and even in the pest control industry. Knowing your enemies, understanding their behaviors and mining for additional information can help PCOs defeat their foes.

One person working to understand stored product pests, a growing pest problem in the United States, is Dr. James Campbell, a research entomologist with the United States Department of Agriculture’s Biological Research Unit, Grain Marketing and Production Research Center in Manhattan, Kan.

Integrated Pest Management (IPM) focuses on four areas today, Campbell said during a presentation about advances in understanding stored product pests during NPMA’s PestWorld 2007 in Orlando, Fla.

The first is prevention, or “keeping pests from infesting the first line of defense.” If pests become established in a facility, the second step is avoidance — trying to keep them away from the product. The third area, and one that Campbell believes is most critical, is monitoring. “It is more than just a one-shot picture of what’s going on,” he said. “You need to track through time.” If the other lines of defense do not work, the fourth area is suppression, such as pesticide application or heat treatments.

ENVIRONMENT. Insects can enter facilities in different ways: They are brought in with infested material or migrate into the facility from the outside. Additionally, “insects can just be persisting in the structure of the building itself,” Campbell said.

Knowing your enemy means knowing that the pests are searching for resource patches, which could range from a single kernel of corn to a hole in a package to a crack in the floor where spillage accumulates. Insects are not stationary either; they will move from one resource patch to another throughout a facility, creating a broader area of infestation.

MONITORING. Campbell suggests many monitoring methods can be used successfully by PCOs to determine areas of infestation. “Visual inspection of product and the structure itself, looking for potential harborages, for spillage, routes of entry and signs of insect activity, is an important part of any pest management program,” Campbell said.

He suggests adding either commercial pheromone traps or hand-made monitoring stations, and using fluorescent powder and pheromone lure. As the insects land, they pick up the powder, and as they migrate through the facility and land in another trap, the PCO can determine their range. Especially useful in this stage are sticky cards, not only in the facility itself, but also outside near the entrances.

All of the information harvested from various monitoring tools must be deciphered. “Plot trends and trap catch over time,” Campbell says. “Identify hot spots.” He suggests using contour mapping. “Instead of looking at numbers, create a map.” More often than not, this shows that infestations may be localized, instead of spread across the entire facility.

LIFE STAGES. An important issue to remember is that the pest population is not all adult. Various life stages are represented in facilities, which means that one solution will not kill the entire pest population. “If we know about the distribution of life stages within a facility, it might help a PCO select their treatment method,” Campbell said. Lab studies are underway to see how combining pyrethroid and IGR effects pest suppression. “We expect to see more of an impact on immature stages,” Campbell added.

LAB TESTING. Campbell and his colleagues continue to conduct small-scale experiments, using different landscapes and pests. One of the most frustrating aspects in food facilities is the inability to reach all insects. “An entire population may not get the full dosage of treatment,” Campbell says. Using small-scale testing, the researchers are trying to overcome this problem.

However, Campbell warns that “each site is unique and we cannot generalize. If this treatment works like this here, it might not work like that there.” He continues, “We can make predictions to guide the selections of pest management, but if something is not working well, it can be modified.”

Another important fact to remember is that one treatment usually is not used in isolation. Campbell and his colleagues continue to look at the integration of various approaches and treatments. This includes ongoing studies to improve existing tools, including traps and trap interpretation, and positioning of the traps.

“We are working with modelers to work on predictive models. These will help us explore predicted effects with certain pest management tactics,” Campbell said.

KNOW YOUR ENEMY. Understanding the pest’s behavior is the first step in being a successful PCO. Using all of the tools developed by researchers is another important step. “I want to stimulate your thinking about stored product pests and how they interact with their environment in regard to pest management,” Campbell said. “How they proceed and interact has an influence on their population structure. The spatial distribution and movement patterns all tie into the population dynamics, and this influences all aspects of IPM, from monitoring to pesticide application to prevention and avoidance,” he said. PCT

First Step: Prevention
Dr. Campbell stresses that monitoring is really the key in a successful IPM program. By using data gathered, combined with visual inspection, a PCO has more tools available to combat pests before they enter food facilities.

Sticky cards can be easily used to determine where insects are entering the facility. It is no surprise that many species of insects are caught around doors. At this point, new rubber gaskets can be installed, and a PCO can continue a monitoring program to see if this action had any effect.

If insects are continuing to enter the facility, monitoring may show that they are entering under the door. In this case, new door sweeps can be installed.
Windows are another source of entry, and updated screening may help to block insects.

Outside sanitation is another area of concern. A PCO can help educate the food facility’s sanitation crew about Dumpster positioning (away from an entrance), and Dumpster cleanliness.

Stored Product Pest Questions
Dr. Campbell suggests a PCO should use the following list of questions in dealing with stored product pests in a food facility:
1) What insect species are present?
2) Where are they located?
3) Was monitoring an important component in determining location?
4) How many pests are present?
5) Are the numbers increasing? (Just because there’s one doesn’t mean there’s a problem)
6) Is this just incidental or an increasing problem?
7) What is the best treatment in response to the presence of that pest?
8) After pesticide has been applied, how effective was it?

The author is a frequent contributor to PCT.