[Termite Control] My Two Cents

Recently, I was asked in a legal proceeding, "Why didn’t the pest control company just kill the termites? After all, this is not rocket science." While I did not give the answer that I would have liked to, it did cause me think about how the results of our work with termites here at Texas A&M have changed my perspective on termite biology and control. The attorney was right — controlling termites is not rocket science — protecting the value of their homes is more important to homeowners than Tang or Velcro™ (which were developed as a result of the space program). Termites potentially can cause damage to every home and business. While the estimated losses to termites vary with the source, we can all agree that it is in the billions of dollars every year, year after year. Following are some general concepts that relate to the science associated with the management of subterranean populations.

TERMITES ARE UNIQUE ORGANISMS. Termites are among the oldest of all insects, with fossil records going back millions of years. While they have had to adapt to changing environments through the ages, they have remained very successful. In fact, they are unique in their abilities to digest cellulose either directly and through the association with bacteria and protozoans in their hindgut. The end result is that termites have the ability to locate and utilize cellulose in various forms as a food resource. There are very few other animals that have this ability, so termites have very little competition for one of the principle resources for life, which is food.

In biology, we discuss and research the niche that organisms occupy complex environments. The niche is the place where the termites live and make their living. In order to survive, there are requisites for life that must exist in, or near, their niche. These resources include food, moisture, atmosphere, harborage, a means of elimination of their waste products, and members of the same species for reproduction and colony maintenance.

In the management of termite populations, we are determining the status of these requisites. When they exist, we would generally conclude that we have "conducive conditions" necessary to attract and retain termites. With this in mind, the rest of the Principle of Niche is that "no niche goes unoccupied through time." In other words, unless the requisites for life are removed or contaminated with toxic materials, a population of termites will return to the site and reinfestation will occur. How soon that happens is one of the many variables that must be examined. The most practical aspect of this concept is based on how long a termiticide will last in the soil around a house. Once the chemicals have degraded below the "threshold limit value" then that niche will be reoccupied. If water leaks and defective construction elements are correct, these mechanical changes also may change the potential niche and reduce the probabilities of reinfestation.

THE SCIENTIFIC METHOD. The scientific method is an approach for the discovery of truth through the designing of experiments that address specific questions. The method itself is well established by usually beginning with the idea that a hypothesis is formulated, this is then tested in replicated experiments, the data from the experiments is analyzed, then conclusions are drawn, and the hypothesis is either accepted or rejected. In the testing process it is imperative that the experiments be repeated a number of times so that the probability of determining the correct results are increased. While it may be a fine point, we generally base the research on the "null hypothesis" which means that we assume that there are no differences between a treatment (product) until such time as it is proven that a real difference exists. This approach also uses non-treatment controls against which treatments are compared. By doing this, it ensures that the results observed are due to the treatment rather than some other factor.

EIGHT THOUGHTS. What we at Texas A&M have learned about termites:

Termites will continue to be a challenge, and while we have new methods and products that are effective against these pests, they will survive through time. We may be able to manage their populations for periods of time, but through time they will occupy all available niches available to them.

The biology of subterranean termites is still under investigation. We have learned a great deal about the reproduction and survival of termites in the past few years, and there are still a number of things that are not understood, or have not even been studied yet. The fact that they have survived for millions of years is truly an indication that they will continue to be a factor in the future. The question as to whether termites forage randomly, in fractural patterns, or directed patterns is interesting, but has little to due with the control of these insects. In our work, termites will exhibit all types of foraging behaviors depending on the size of the colony and their immediate need for food or water sources. As a result, when we learn something new about termites and their biology, it should be subject to discussion and debate, but it should not be related to a specific product, company or institution.

Those termites will re-colonize or return to areas where they have been excluded or controlled if and when the excluding or controlling agent or device is removed, degraded or disturbed. Again, if the resources for life are present, the niche will be filled.

All of the liquid termiticides that we have tested have been effective in managing termite populations, and can be used to achieve the goal of protecting the treated structure. There are differences in how long the termiticide will be effective in any given environment. The length of efficacy is determined by many factors, a few of which are the types of soil, the chemical composition of the soil and the environmental conditions where the applications were made. One of the main things that we have learned about liquid pesticides is that they are "passive," meaning that they are effective from the time of application up to and until the time that they degrade below the threshold limit level or are disturbed. We also have demonstrated on numerous treated structures that both repellent and non-repellent termiticides can be effective even though they provide protection in slightly different ways.

When using repellent products, it is important to be as thorough as possible in the application procedures. It is obviously imperative that thorough applications be made, as there is a direct correlation between full treatments and the level of protection that is provided to a structure regardless of whether the product is repellent or not. Our research results clearly indicate that all termite entry points need to be treated and that any places where termites are found in a house must receive an application of chemical. Incomplete treatments are a prescription for failure.

Termite baits are effective in managing termite populations. The use of baits is an "active" system, and inspection and maintenance of the monitors and baits is critical to their success. Because there are a number of steps in the baiting protocol, it is important to optimize each step to ensure that the entire process is completed or control will be unlikely. For this, and due to litigation directed at our industry, it is our recommendation that when baits are used, that liquid termiti-cides also be used as a spot treatment at the entry point. This will provide some probability that the structure can receive immediate protection, since the baiting control method can be lengthy, taking from months to years.

Non-chemical control measures can be used effectively in protecting structures from termite invasion. If termites cannot enter a structure there is a low probability that they will be able to eat the cellulose and cause damage. These physical barriers require maintenance to ensure that they remain in place, and that they intercept the termites before they enter the structure.

Despite the belief on the part of some researchers, it is not possible to exactly determine how long a structure has been infested with termites. There is no scientific method yet devised to make these determinations. There are too many needed variables to be able to validly "date" termite damage. It is possible to tell if damage occurred after renovations or repairs, if the dates of those alterations are known, but even then it would not be known exactly when the termites found the new construction elements and when their feeding actually began.

Finally, because the management of termite populations continues to be a dynamic series of processes, it is important not to base the future of your company on a single product, device or approach. Maintain an open mind, ask to see scientific data, and make sure that all claims make "biological sense." Termites will continue to evolve, pesticides and control measures will continue to be introduced, the Environmental Protection Agency will continue to suspend or cancel products as well as register new ones, and termites will continue to eat cellulose.

FINAL THOUGHTS. We express appreciation to all those who support research associated with termites. There is so much to be learned, and so few resources available to do this work. There is a continuing need to examine even the most basic of biological factors associated with termites, for it is from these types of studies that the next generation of management technologies will be derived.

The author is professor and endowed chair at the Center for Urban & Structural Entomology, Texas A&M University. He can be reached at rgold@giemedia.com.