GARDENING

The evolution of termite treatments


Published: Saturday, May 25, 2013 at 6:01 a.m.
Last Modified: Thursday, May 23, 2013 at 2:50 p.m.

Several years ago, I was summoned to examine a horse barn that had a number of wings — perhaps thousands — along the center aisle. It wasn't hard to conclude this was a large swarm of the eastern subterranean termite.

In Florida we deal with several types of termites, but those of primary concern currently are the subterranean termite and the drywood termite. While it is possible to have drywood termites in this central portion of the state, they are more likely to occur in coastal areas. Drywood termites live in wood in the interior of structures and are controlled by tenting the structure with canvas and applying a fumigant to eliminate the colony. I have observed over several years in Marion County that only about 5 percent of termite questions involve drywoods, while about 95 percent of the termites we deal with are of the subterranean variety. For this interior part of Florida, the subterranean is the termite of greatest concern and control methods have evolved considerably over the past 25 years.

Subterranean termites live in underground colonies and forage for cellulose, a material found in wood products. These termites serve a very productive role in nature, assisting in the breakdown of logs, lightning struck trees, etc. Their foraging is random and once they locate a food source, they leave a scent trail so other members of the colony can find their way to the meal. Understanding the nature of termite foraging activities, dietary habits and lifecycle has enabled scientists to develop methods to protect structures. Homeowners are faced with several decisions in determining which method of control will be best for their needs. Cost, expertise of the service provider (particularly the technician making the treatment application), and terms of the contract are all considerations that require careful study. One factor in this process is the method of protection which largely comes down to the choice between a barrier treatment or a baiting system.

The first of these methods is often referred to as "trench and treat" or a barrier system. A shallow trench is dug a few inches away from the foundation, the chemical is applied to the soil and the trench is covered. This places a chemical barrier between the structure and the termites, forcing the insect to pass through the barrier in order to feed. At one time repellant materials, chemicals that were unpalatable to termites, were the only option. The disagreeable nature of these repellants drove termites away from the structure and encouraged them to conduct their foraging activities elsewhere. In more recent years very effective poison materials have been developed. Termites are unable to detect these poisons and when they pass through the material the poisons adhere to their body, eventually resulting in death. Poison materials for termite control include Termidor, a material that acts on the central nervous system; Premise, a product that also acts on the central nervous system; and Altrisett, a material that paralyzes the mouthparts of the insect, making it impossible to feed. Over time these products break down in sunlight and temperature, hence replacement is recommended on a five year interval.

Another option for termite control is the use of baits. In this instance, bait stations are located on set intervals, usually ten feet, around the structure. This technology takes advantage of the foraging characteristic of the termite and offers a bait product that prevents the termite from molting. Over time the termite outgrows the hardened body shell and trapped inside, dies. Because these act slowly, termites continue to feed on the bait several days and leave a scent trail for others to follow to the bait station, eventually resulting in elimination of the colony. Initial concepts of these bait stations offered wood and replaced it with bait when there was evidence of termite feeding. This required quarterly inspection of the stations, a very expensive proposition. In more recent times, baits have been developed that are good for one year and baits are initially placed in the stations, rather than replacing wood stakes with bait once feeding is evidenced.

Extension often receives questions about do-it-yourself termite control, but this is not recommended. Products available to homeowners simply are not able to kill the large quantity of termites that make up most colonies.

The University of Florida has a publication, ENY-219/MG237: How to Buy Pest Control Services, that will provide pointers to residents on selecting a pest control firm. This may be obtained at edis.ifas.ufl.edu or you may obtain a copy by calling your local Extension Office.

Termite protection is a costly, but necessary expense in protecting your home. As in any contract, it requires a careful and thorough vetting process to insure you get adequate and effective coverage at reasonable rates.

David Holmes is Marion County extension director. Contact him at david.holmes@marioncountyfl.org.

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