The Role Of Pesticides In IPM

Integrated Pest Management — has any term created so much confusion, uncertainty or diversity in interpretation in the pest control industry? If you spent a few days searching a variety of literature — including industry magazines, newspapers, government publications and regulations — you would discover as many definitions of IPM as there are mentions of the acronym "IPM."

Where does all this leave the typical pest management service professional, out on the streets daily, trying to serve his or her customers’ needs? Why should these professionals care about the latest definition of IPM, especially when surveys show the general public has no clue what IPM is and what the term means? It’s difficult to get excited about something when the most important people to your business — your customers — don’t care about it. Your customers are interested in the bottom line — keep their building free of pests.

Still, our industry needs to start caring because special interest groups and governmental regulatory agencies are pushing the IPM agenda with one goal in mind — the ultimate restriction and possible elimination of pesticide use in the urban environment. When one tact fails, another is formulated to take its place. As with most regulations, those involving IPM commonly contain unclear language and generally place the greatest burden on pest management professionals to accomplish the goals of IPM. This happens despite the fact that building owners bear the greatest responsibility and pest management professionals have little authority to dictate the changes necessary to minimize the need for pesticides.

IPM IN SCHOOLS. The most significant debate revolves around pest control in schools. Many states now have regulations that require schools to implement an IPM program. Most school systems still purchase pest control services via a process that typically accepts the lowest bid regardless of the outlined pest control specifications in the bid. Will the winning company have the time to analyze the pest control needs of the school and prepare the detailed reports necessary to complete the tenents of IPM? Even so, will the school have the money to implement the recommendations of the professional? Many highly competent, IPM-practicing companies do not even bother to bid schools (and similar institutions) that acquire services via a low-bid process. The investment of time holds little promise of real return.

IPM has its greatest success only in those few schools and businesses committed to investing both the time, money and resources to making IPM work. Such schools and companies realize the value of their pest management professional lies not in how inexpensively he or she can complete the service but in the knowledge and experience he or she has to analyze their pest control situation and make reasonable, practical recommendations. A spirit of cooperation is inherent in these relationships where both parties accept their share of the responsibility to achieve the goal of a pest-free building while minimizing the need for pesticides.

One overriding theme, however, from special interest groups and government agencies historically antagonistic to pesticide usage, is their thinly veiled goal of complete pesticide restriction. Common sense and science often does not make much of an impression in suggested practices and regulations. A prime example is the exultation of boric acid as the "safe" alternative to commonly used synthetic pesticides. Not to disparage boric acid — it is an excellent and much-needed material — but its LD50 is much lower than that of many products at the end-use rate (e.g., liquid dilution or bait). The truth is that any product can be misapplied, but if the product is applied to specific locations where a pest resides, risk of any kind to building occupants is minimal at best. Boric acid may be the most misused product in the United States when in the hands of some individuals, such as homeowners and school custodians, who have no training in pest control and pesticide handling.

USING PESTICIDES. Is it possible to eliminate a pest infestation without using a single pesticide application? Well, yes…depending on the situation. For example, a minor mouse infestation can be eliminated using traps or a fly infestation can be controlled via improved sanitation and exclusion. Reality, however, demonstrates applications are needed in varying degrees for various pest infestations. It is the professional who must investigate, analyze and decide which techniques — chemical and/or non-chemical — will solve the infestation to the customer’s satisfaction. Despite the contention of many IPM enthusiasts outside the pest control industry that "action thresholds" be enacted for each pest, the fact remains that the typical American citizen demands action when even one pest is seen. Tolerance of pests of any kind is minimal, even in schools and public buildings. Does "action" mean pesticide application every time? No…but more often than not, some type of application is warranted. To believe that anyone can achieve zero pests without the use of pesticides is short-sighted.

What is the role of pesticides in IPM? To meet the basic tenent of IPM that pesticide use be minimized, one must focus first on the underlying causes of the pest infestation. Information is critical and acquiring such information can be time-consuming, especially the larger and more complex the building. This process is even more difficult when approaching service for the building for the first time. A critical first step, prior to inspection, is to analyze past pest control service records and pest-sighting logs, if they are available. The more months or years of records, the better the overall conclusions for planning pest management services.

It has been this author’s experience and belief that every building has its historic pest-infestation issues. This fact is especially true for larger buildings. A significant amount of the space in buildings will rarely, if ever, require pest control services, yet building managers often insist that every part of a building be serviced regularly. Why?

By using past pest control records and plotting pest activity on floor plans of the facility, one can determine the highest risk areas for activity. Most areas of the building can be placed on an as-needed or less frequent service basis, permitting the service professional to concentrate efforts on the key sites where activity is anticipated. Additionally, such high-activity areas must be investigated to determine the underlying causes for the high activity in the area. If such causes can be discovered and corrected, it is easy to see where pesticide use can be reduced dramatically.

Effective IPM programs require continued analysis based on current pest activity information. IPM is decision based, meaning the service professional determines the steps necessary for each pest situation, no matter how small. Monitoring is important, but it can be practiced to such an extent that it is detrimental to the success of the overall program. Monitoring should be confined to those areas where pest activity is possible but not in areas requiring regular close inspection. Monitoring traps are too often placed throughout a room or building with little thought given to the trap’s true purpose.

For example, a classroom might be the recipient of a half-dozen monitors. Has the classroom ever had previous mention of activity? If so, what type of pest and where would it likely have originated? Placing traps requires they be checked — which means an investment of time — time that might be better spent elsewhere. Place each monitor with a goal in mind — to target likely activity involving the key pest. Areas with little risk of pest activity typically do not need monitoring, especially on a regular basis.

LIMITING PESTICIDES. All the above-mentioned steps have one goal — to pinpoint active pest harborages. Only once the site (or sites) where a pest resides is known will the decision to use a pesticide be necessary. The first questions that must be asked are whether the infestation can be controlled or eliminated using non-chemical means and what effect such efforts have in minimizing the need for pesticides.

For example, a population of German cockroaches in a school kitchen or classroom may be greatly reduced by vacuuming, but this step will not result in eliminating the infestation. Bait application will likely be necessary as well as treatment of certain wall voids with an inorganic dust product. By vacuuming, considerably less pesticide is needed to achieve the desired result of zero cockroaches. The use of baits, instead of residual products, further reduces the amount of insecticide used because baits are applied in small amounts directly into cockroach harborages. Residuals may require treatment of a greater number of cracks and voids than is needed when using a vacuuming/baiting approach.

Another example might involve the sudden appearance of black vine weevils in a school hallway and offices. The weevils are originating in the ivy used in the landscaping outside these areas. Weevils inside can be removed by vacuuming. How they are entering the building must be determined and steps must be taken to exclude the weevils. Short-term treatment of the ivy will halt the weevil invasion, but long-term, the school must be convinced to remove the ivy completely and change the landscaping to an alternative planting.

SUMMARY. Often, pesticides are necessary to remedy an existing or new infestation of pests. Following this step, the conditions creating the infestation must be addressed. If not, additional treatments will likely be necessary. Preventive applications (e.g., perimeter treatments) have little place in IPM. It makes little sense to attempt to treat everywhere a pest might show up. IPM dictates that the service professional focus on discovering where pests are active outdoors or might otherwise gain access to the building and then take appropriate steps, including treatments, if necessary.

Some situations might call for extensive use of pesticides while others require little, if any, treatment. Service professionals must be prepared to gather and analyze pest-related information and then make appropriate decisions regarding treatments. Pesticides have a significant role in structural integrated pest management. Let no group or person try to convince you otherwise. Pesticides must also be used judiciously, however, by applying them where they will achieve the best result.