Photo courtesy of Gerald Lenhard, Louisiana State Univ; insectimages.org	Termite Treatments Are Diverse Part 2
By Nathan Riggs - Extension Agent - IPM, Fire Ant Program Texas Cooperative Extension - Bexar County

Last week, our Extension article gave a little bit of information about termites and their habits. This week we will touch upon the confusing world of termite treatments, and how they work in theory.

First and foremost, it should be noted that termite treatments in and around a home or structure should be applied by a licensed applicator. Licensed applicators should have a license issued by the Texas Structural Pest Control Board (www.spcbtx.org, (512)305-8250). If you have any questions regarding termite treatments or pest control operator practices, don't hesitate to call the number above.

Now, onward to the good stuff! Prior to 1988, pest control operators were blessed with chemicals such as heptachlor and chlordane to use against termites. These substances could be applied and would protect against termites for 20 to 30 years. Unfortunately, misuse and concerns over pesticide residues in the environment have resulted in cancellation of these chemicals in the U.S. Many other products and chemicals have taken the place of chlordane and heptachlor in the years that have followed, and these have an expected soil life of three to seven years. Bait systems have also become popular alternatives to chemicals. We'll look at both of these strategies a little closer.

Chemical treatments for termites are usually applied in a trench around the exterior foundation, injected through holes drilled in the slab, or applied as spot treatments to affected areas. Spot treatments are very uncommon in today's strategies.

The trenches are dug 6 inches deep and 6 inches wide where the foundation meets the soil. Termiticides are then injected with a rod into the trench another 12 inches or so deep. This sets up a barrier in the soil that either repels the termites or kills them as they dig into it or soon after.

Termites working trails in wood. Photo courtesy of UMN University Extension

Subterranean Termite Workers Photo courtesy of PSU Extension

Because termites frequently invade homes around plumbing, some situations require termiticide applications around the plumbing openings in the foundation. Occasionally, small holes must be drilled through the slab inside of the house in order to treat under the slab, along the inside of the outer foundation wall, or around commodes or other plumbing throughputs. The drill holes are then filled in after the treatment.

When building a home or additions, it is possible to treat the timbers and studs with borate chemicals to make them more resistant to termites. Check with your local pesticide wholesaler for more information on what is available.

There are products available over the counter that will kill termites on contact in infested wood. Check the label for approved treatment sites. These products give instructions for spot treatments and trench applications. From chemicals, we turn to the newer baiting systems and how they affect termites.

Today's baiting systems for termites act in one of two ways: 1) prevent the termites from shedding their skin, or 2) kills them with a slow-acting stomach toxicant. The active ingredients in these systems work well as they are intended. These systems are implemented as follows: a spike-like bait station containing a replaceable bait (wood or similar material) matrix is placed at 10-foot intervals around the perimeter of the structure at a distance of 3 feet from the foundation.

Once placed in the ground, these stations are monitored periodically until they are "hit," or discovered by the termites in their random foraging patterns. In the San Antonio area, tests conducted by researchers at Texas A&M University show an average time to "hit" a bait station of about 200 days. Once termites "hit" a station, the bait is replaced with active ingredient and the termite workers begin taking bait back to the colony. Once the active ingredient is introduced, the average time until no more termites feed on the stations is approximately 30 days. Baits do not kill the termites as quickly as regular termiticides do, but they are virtually non-toxic to everything but the termites.

With safety and other questions in mind, let's consider some pros and cons of these approaches. Benefits of liquid termiticides include fast action, residues in the soil of three to seven years and lower cost. Benefits of baiting systems include very low toxicity of active ingredients, and no need for trenching or drilling holes in foundations. Cons for liquid termiticides include stronger pesticides, invasive application methods and need for re-application if the barrier is broken. Cons for the baiting systems include high expense, reliance on termites to find the stations, and lack of protective barrier as with liquid termiticides.

Some companies are offering bait/trench combinations for termites which deserve consideration as a "best of both worlds" strategy.

Before closing, we might mention a couple of words about the over the counter termite stakes. Because they come pre-loaded with active ingredient, they usually last no more than 30 days or so before they require replacement. They also did not perform well in tests conducted by researchers at Texas A&M. Perhaps these products will continue to improve to the point where they do work in a reliable manner.

As you can see, treating termites is a complex undertaking. With treatment costs running anywhere from $500 to $3200 or more, a homeowner must be thoughtful and deliberate when choosing a treatment method and pest control service. Before making a decision, get bids from at least three companies using similar treatment methods for your particular situation. For more information on termites, check the Bexar County Extension website at http://bexar-tx.tamu.edu or the Texas A&M termite website at http://termites.tamu.edu.

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