The following information is adapted from Kentucky Pest News, Number 840, March 29, 1999 . By Mike Potter, Professor of Entomology, University of Kentucky). Similar information is on the Iowa State University Integrated Pest Management web site at http://www.ipm.iastate.edu/ipm/iiin/termites/ .
For approximately 50 years, the standard method of controlling subterranean termites has been to apply a liquid insecticide (termiticide) to the soil around and under the house. The goal of this treatment is to block all potential routes of termite entry into the structure. This treatment is referred to as a "barrier" treatment. Termites attempting to penetrate the barrier (that is, treated soil) are either killed or repelled.
The new alternative form of termite treatment, called termite baiting, is an entirely different concept. With this approach, tiny amounts of insecticide are deployed like edible "smart missiles" to knock out populations of termites foraging in and around the structure. Foraging termites consume the bait and share it with others in their colony. The result is a gradual decline in termite numbers and possible eradication of the termite colony. A comprehensive baiting program maintains a termite-free condition on the customer's property through ongoing monitoring and rebaiting as needed.
Termite baits (a slow-acting chemical ingredient mixed in a termite food such as wood, paper or cardboard) are put in bait stations, that is, perforated plastic tubes or boxes that hold the food/bait mixture until the termites consume it. Some bait stations are installed below ground out in the yard and others are positioned within the structure in the vicinity of active termite mud tubes or feeding sites. Below-ground stations typically contain untreated wood strips until termites are detected inside the stations. Then the wood is replaced with active ingredient treated material.
Barriers and baits, though presented as alternatives, may be used alone or in combination with each other, and in combination with wood treatment and available non-chemical controls.
Termite Bait Products
There are four bait products on the market. Three are sold by professional pest control firms while one is marketed directly to homeowners.
Sentricon Colony Elimination System from Dow Agrosciences
This is the first and most widely used termite bait. Hundreds of thousands of structures have been baited with Sentricon since its introduction several years ago. Sufficient independent research trials have been conducted to confirm its effectiveness when properly installed and diligently serviced by an authorized pest control firm.
FirstLine from FMC
This relatively new product is more commonly used in combination with other forms of treatment, rather than as a "stand alone" treatment. Limited research conducted so far has been inconclusive and the impact of the bait on active termite infestations has been difficult to determine. The manufacturer is continuing to modify the product to optimize performance.
Exterra Termite Interception and Baiting System from Ensystex
This is the newest bait on the market (introduced last year). As with Sentricon, Exterra is often used as a stand-alone treatment. The active ingredient in both products disrupts the molting process in immature termites. The Exterra in-ground plastic stations are brown and box-shaped (Sentricon's are green and cylindrical). The untreated wood monitors are flat and affixed to each of the four sides of the station. When termites are found feeding on the wood monitors, the active ingredient is introduced via treated, shredded paper toweling that is loosely stuffed into the center of the station without removing the monitors. It is too early to know how well Exterra will perform though preliminary results have been encouraging.
This do-it-yourself termite bait is often available at home centers and lumber yards. Late last year, the Federal Trade Commission (FTC) and eight state Attorneys General filed a complaint in U.S. District Court alleging that the advertising claims about the product are deceptive and unsubstantiated. As part of a settlement agreement reached last week, the manufacturer will be permitted to sell Terminate in 1999, but with substantial modifications in their advertising claims. Notably, they will no longer be able to state that use of the product alone is effective in preventing or eliminating termite infestation or damage to homes. The manufacturer can advertise that the product "kills termites," but they must also state that Terminate is not recommended as sole protection against termites, and for active infestations, homeowners should get a professional inspection. Do-it-yourself termite treatment is still not recommended by Iowa State University Extension Entomology.
To Bait or Not to Bait...
There are no easy answers when trying to decide which form of treatment to purchase. Advantages to homeowners for using bait include, little or no indoor disruption (stored items don't have to be moved, carpeting/flooring won't have to be pulled back, floors are not drilled). If there is no drilling, there is no noise, no dust, and no pesticide in the house.
Some structures have construction features that make it difficult or impossible to treat with conventional methods (e.g., wells, cisterns, drainage systems, sub-slab heating ducts, and inaccessible crawl spaces). Buildings with hard-to-treat construction elements are logical candidates for baits. Baits are non-volatile, non-leachable solids. They can be used in the most sensitive treatment situations with little or no impact on the environment.
The biggest disadvantage common to all bait systems, is that baiting is a slow, prolonged process. Several months may pass before the termites find the untreated, below-ground monitoring stations and begin to feed on the bait. Consequently, it is not uncommon for the elimination procedure to take more than a full year to complete. Although usually minimal, some degree of termite feeding and damage may occur before the slow-acting bait takes effect.
Baiting programs may be slightly more expensive than conventional treatments. The baiting process requires multiple visits to monitor for termites, and to add or replenish baits as needed. Homeowners should consider both the initial treatment price and the annual renewal fee in making their purchasing decision. Failure to maintain the annual service agreement is a prescription for disaster with baits, since there is no residual pesticide left in the soil after the termites have been eliminated. Ongoing structural protection depends upon diligent monitoring for new evidence of termites.
Reasons to choose a conventional barrier treatment include:
- limited available income;
- simple, straightforward construction;
- tolerance toward having the wall-to-wall carpeting pulled back and the basement/slab floor, patio, porch, etc. drilled, and
- a renewable service agreement (guarantee) from the pest control company.
In summary, termite prevention and control is a very complex and frustrating topic with no easy answers. Ultimately, the consumer must make the decision. Shop around, get several estimates and explanations, and become fully informed about the processes and your options.
This article originally appeared in the April 9, 1999 issue, pp. 35-36.
Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on April 9, 1999. The information contained within may not be the most current and accurate depending on when it is accessed.