by Jay Romano, NY Times

 

ACCORDING to some estimates, termites have been nibbling away at wood on the earth for at least 100 million years. For most of that time, of course, few complaints were registered.

As soon as people came along and started building homes out of wood, though, the relationship between humans and termites became decidedly antagonistic. The bugs would do everything they could to get inside people's houses and eat them, while the people would do everything they could do keep them out. In fact, pest control experts say, until relatively recently the primary strategy for dealing with termites was to create a chemical barrier around the house to act as a moat of sorts to keep termites at a respectable distance.

In recent years, however, pest control professionals have adopted a couple of new strategies for dealing with termites. In short, rather than merely repel the insects — leaving them to regroup and fight another day — they instead try to eliminate them. For good.

"Termites cause billions of dollars in damage each year," said Michael F. Potter, a professor of urban entomology at the University of Kentucky. "They primarily feed on wood, but they may also damage paper, books, foam board insulation and even swimming pool liners and filtration systems. And oftentimes, there will be no sign of the termites themselves."

Dr. Potter explained that in most cases, termite colonies — which can contain hundreds of thousands of insects in interconnected subcolonies — are underground, as many as a couple hundred feet from where the termites are feeding.

Worker termites travel through tunnels in search of food — basically, anything made of cellulose will do — and then return to the nest with their booty. If the termites encounter an obstacle — a concrete foundation wall, for example — they will construct pencilwide mud tubes on the surface so that the termites can travel inside the tubes without being exposed to the air. Once they hit wood, they start eating.

"Termite-damaged wood is usually hollowed out along the grain," Dr. Potter said, adding that termite feeding — and the damage it causes — can remain undetected even in wood that is exposed because the outer surface of the wood is usually left intact. "An infestation can go undetected for years, hidden behind drywall, paneling, floor coverings, insulation and other obstructions," he said.

While termites do most of their work out of sight of the homeowner, there is a moment when some termites in a colony emerge from their hiding place to enjoy one brief shining moment in the sun.

"Spring is typically when large numbers of winged termites, known as swarmers, emerge," Dr. Potter said. "Triggered by warmer temperatures and rainfall, the winged termites emerge from the colony and fly into the air. The swarmers then drop to the ground, shed their wings, pair off with a mate and attempt to begin a new colony."

In most cases, he said, swarmers emerge outside. In some cases, however, a swarm might emerge in a living room. In either case, it is not necessary to witness an actual swarming to know one has occurred; discarded wings and some dead termites are the evidence.

"The discovery of winged termites inside a home almost always indicates an infestation warranting treatment," Dr. Potter said. "And in most cases, ridding a home of termites is a job for a professional." (Termites can be differentiated from flying ants, which are usually less of a problem, by their appearance. While flying ants have constricted waists, elbowed antennae and fore-
wings that are longer than the hind wings, termites have uniform waists, straight antennae and four wings of equal size.)

The most common method for dealing with termites, Dr. Potter said, involves injecting a chemical in the soil around the house, drilling through concrete where necessary. The substance injected — called a termiticide — provides a chemical barrier around the structure, which repels termites.

Over the past several years, however, two new methods have emerged for dealing with termites. One involves the use of nonrepellent but lethal chemicals that allow the termites to dig through the treated soil, ingesting the substance and ultimately transporting it on their bodies to other termites.

The other involves the use of buried wood-filled containers to provide foraging termites with a convenient meal. Once termites have entered the station, the wood is replaced with a chemical that ultimately kills the termites that ingest it.

Karl J. Kisner, senior marketing manager for BASF Professional Pest Control, said that two recently developed products manufactured by his company — Termidor and Phantom — are intended to kill termites rather than repel them.

"When you put down a treatment zone of Termidor, the termites can't see it, can't smell it and can't feel it," he said, explaining that the chemical is injected in the ground around the perimeter of the house. "But they pick up the material on their bodies and unknowingly carry lethal doses back to their colony, killing others they contact on the way."

Both Termidor and Phantom — which are odor free and will kill termites for at least five years — can be applied only by pest management professionals trained in the products' use. The cost of treatment varies widely, Mr. Kisner said, depending on the property being treated, with an average house costing $1,000 to $1,500.

Another nonrepellent termiticide is Premise Liquid, manufactured by Bayer Environmental Science in Montvale, N.J. While Phantom is available in all states, neither Termidor nor Premise has yet been approved for use in New York.

Another way to eliminate termites — but one that does not require injecting chemicals in the soil around the house — is to put the chemicals only where the termites are.

Arthur Katz, president of Knockout Pest Control in Uniondale, N.Y., said his company uses the Sentricon Termite Colony Elimination System, a procedure that can kill an entire termite colony using just a few grams of chemicals.

With the Sentricon system, Mr. Katz said, plastic "monitoring stations," about the size of a tall soda can, are buried in the soil around the house every 10 feet or so, with the top of the station flush with the ground. The stations — which have holes that permit underground access by termites — are then filled with wood to provide an appetizing pit stop for foraging termites. Every 30 days or so, a technician inspects the stations to determine whether any termites are feeding on the wood.

"Last year, we introduced a new technology that allows us to electronically monitor the stations," Mr. Katz said. Using a special circuit board in the station, technicians can determine whether termites have entered the station without having to open the top.

"What we know about termites is that they randomly and constantly look for food," he said. "So over a period of time, ranging from several weeks to several months, some termites in the area will find themselves in one of the stations."

Once termite activity is detected in a station, Mr. Katz said, a substance known as hexaflumuron is placed in the station. "Hexaflumuron is an insect growth regulator," he said. "When termites eat it, they can no longer shed their skin. And when they can't shed their skin, they die."

Like the nonrepellent liquid termiticides, the Sentricon system relies upon the termites themselves to spread the substance throughout the colony.

"On average, it takes about 90 days to eliminate a colony once termites have started feeding on the hexaflumuron," Mr. Katz said, adding that if active termite mud tubes are present, the Sentricon stations can be installed directly on the tube, thereby reducing the time it takes for termites to find the bait.

While the cost of the Sentricon system varies depending on the size of the house, Mr. Katz said, an average house can be treated for about $1,400.

Cindy Mannes, director of public affairs for the National Pest Management Association, a trade organization based in Dunn Loring, Va., said homeowners should ensure that a pest management company hired to treat a house is state-licensed and insured. "You should also ask if they are members of any state or national pest control associations," Ms. Mannes said. "And if a sizable amount of money is involved, you might want to get bids from several companies." Additional information about termite control is available on the association's Internet site, www.pestworld.org.