Safe Termite Control

Image Gallery Termites play an essential role in nature. The only problem is that they can't be distinguish between a dead tree and a floor joist.

With the leading termiticides now off the market, containing wood borers is difficult—but not impossible.

By Karla Harby

By helping clear the forests of dead trees, termites play an essential role in nature. Their slow but certain work creates pathways for fungi and bacteria to further decompose fallen timber, thereby preventing the forests from becoming clogged with deadfalls, clearing routes for new growth and enriching the soil.

But termites can't distinguish between a dead tree and a floor joist. The best estimates of structural damage caused by termites put the cost somewhere in excess of $750 million a year in the U.S. alone. No state except Alaska is entirely free from the pests, and though areas with colder climates have fewer problems than do warmer parts of the country, the proliferation of subdivision building in forested areas has encouraged pockets of termite activity in even the least susceptible locales.

It's not unusual for a termite infestation to cost a homeowner several thousand dollars. According to entomologists and termite specialists at the U.S. Department of Agriculture (USDA) Southern Forest Experiment Station in Gulfport, Mississippi, about 95% of this damage is caused by subterranean termites; the remainder is attributed to the dry-wood termite, found principally in the South.

Since World War II, the most popular approach to termite control has been to spray the ground around and under infested struct ures with chlorinated hydrocarbons—a group of potent, long-lasting chemicals that includes chlordane, aldrin, dieldrin and heptachlor. These compounds are sprayed directly onto (or into) the soil around a building's foundation, as well as in the crawlspace or the basement.

The sole manufacturer of chlorinated hydrocarbon termiticides has long insisted that its products are safe and effective when properly used. Effective, yes, but persistent health and environmental problems, such as poisoned fishing ponds, contaminated well water and indoor air pollution in some treated homes, prompted New York, Massachusetts, Rhode Island, Michigan and Minnesota to ban the products, and finally led the Environmental Protection agency (EPA) to consider the delisting of chlordane and its kin. Under such pressure, the manufacturer finally acquiesced and "voluntarily" ceased manufacture, effective August 11, 1987, of all chlorinated hydrocarbon termiticides. While these products are still available in some areas, their use is ill-advised.

The necessary demise of chlordane and its relatives has caused quite a stir in the world of termite control, prompting an accelerated search for safer methods of extermination and suddenly making knowledge of how termites live mandatory for homeowners who wish to take preventive as well as corrective measures.