Post-Construction Termite Control Deserves Focus

It is important to understand that the recent PR Notice 96-7 addressed only pre-treatments, and that the issue of post-construction was left silent. Leaving post-construction issues untouched defies all logic.

Because the PR Notice and new labels do not address post-construction treatment, FIFRA 2(ee) can be used to defend less-than-minimum label application rates to be used for post-construction termite applications unless state law prohibits less-than-label rates.

A LAPSE OF LOGIC. Exempting post-construction from minimum application rates and concentrations is not logical, nor is it scientific. It is illogical for two reasons: termite infestations are rarely, if ever, found during construction, and the industry rarely treats for termites in post-construction situations unless there is a strong indication that termites are present. Thus, if termites are present, why would one consider using less product to repel them in the hope of holding them at bay no more than 12 inches from the structure, while also hoping that they’ll remain away indefinitely?

I have heard all the arguments for using less-than-label rate in post-construction treatment, and on the surface they may seem fundamentally sound. However, nothing could be further from the truth. One of the most frequent explanations for using less than full application rates is because the soil is compacted clay and other soil conditions exist to prevent full-label treatment. Another explanation is that the footing is too deep, and therefore, it is impossible to treat that deep (this has been corrected on the new labels). I have also heard PCOs say that based on their experience, less-than-label rate will work, and thus less-than-label treatment becomes the rule instead of the exception.

This fallacious thinking deprives the customer the benefit of the maximum treatment (i.e. protection) permitted by law.

MORE IS BETTER. Extensive scientific information exists to support the concept of maximum concentration and application rate. The efficacy and degradation of termiticides has been extensively studied by the U.S. Department of Agriculture Forest Service, the University of Florida, Texas A&M University, University of Hawaii and others. Regardless of the researcher or location, the results consistently send the same message: more is better. The studies consistently point out that termiticides vary considerably in their persistence and repellency in different geographic locations, from site to site, and even around the treated structure itself.

For more than 40 years, the gold standard for termiticide efficacy has been the research conducted by the USDA Forest Service in Gulfport, Miss. The basic tests are the concrete slab test, which is analogous to a pre-treatment under a slab, and the ground board test, which is analogous to a pre- or post-construction treatment around the perimeter of a structure. The ground board test involves placing a block of wood on top of treated soil; it is the most severe termiticide challenge because the product is exposed to a variety of environmental effects and is unprotected by a concrete slab. Thus, it measures termiticide persistence and repellency in the soil around a structure.

Keep in mind that the Gulfport studies, as well as most other field research on termiticides, are conducted under ideal conditions and occasionally at higher concentrations than the registered products. To achieve reproducible results and for statistical analysis, researchers attempt to optimize distribution and apply the termiticides uniformly; this rarely, if ever, is possible under field conditions.

Despite maximum rates of application and ideal treatment procedures, some products fail to provide 100% protection in one or more sites (i.e. Mississippi, Florida, South Carolina and Arizona) within 1 to 2 years, and most fail to provide 100% protection beyond five years. The 1997 research report on termiticide efficacy can be found on page 43 in the February 1998 issue of Pest Control. Anyone who does termite work with repellent termiticides should look closely at this table, particularly the ground board data.

This article is not intended to be critical of the manufacturers and their products, because they are working within the guidelines mandated by the U.S. Environmental Protection Agency.

However, I am critical of the EPA and how the issue of post-construction treatment and efficacy was ignored in PR Notice 96-7. The agency had the perfect opportunity to strengthen product labels in the post-construction market, but missed the mark. They also could have expanded the registration requirements regarding efficacy to include the growing body of research being developed. However, they chose to stick with tradition — the Gulfport studies. No question, the Gulfport studies are an excellent approach to efficacy, but they are not the only approach and they tell only part of the story.

ARE YOU WORKING ON INSTINCT? I find it unconscionable that some pest control companies continue to use less-than-label rates for post-construction treatments. The evidence continues to mount that the currently registered repellent termiticides do not hold up for extended periods of time, even when applied at full-label rates under ideal conditions. Do you truly know how effective you are in managing termites with traditional repellent termiticides, or are you working on instinct?

Considering the Federal Trade Com-mission’s investigation and consumer litigation, the intelligent thing to do is to maximize termiticide applications and perform periodic perimeter retreats as determined by the label, typically at no more than 2- to 5-year intervals.

Dr. Richard Kramer is president of Innovative Pest Management, Olney, Md.