Nontoxic Termite Killers : Different Tactics: Exterminators use cold, heat, microwave energy and electricity against the wood-chewing pests where people want safety from pesticides.

Drywood termites are the kind most often found in Southern California, and exterminators usually kill them with chemical fumigation.

But new methods using heat, cold, microwave energy or electricity applied directly to infested areas have sparked a debate in the pest-control industry.

Fumigation’s proponents point to its effectiveness at killing every termite in a house, but foes say alternative methods are effective--and safer. The homeowner need not spend the night elsewhere, nor board their pets, remove their plants, protect their food, worry about burglars or put up with a roof or shrubs damaged by a worker erecting a tent.

The nonprofit Bio-Integral Resource Center in Berkeley recommends alternative methods because, where chemical fumigation is sometimes the only way to cure a bad infestation, less-toxic methods can often be used, said Sheila Daar, the center’s executive director. For instance, the hot-air Thermal Pest Eradication method has only been on the market for a few months and isn’t yet widely available, but Anaheim-based Isothermics Inc. is licensing and training other companies to use the method.

Walter Ebeling, UCLA entomology professor emeritus, who has done extensive termite research, developed the patented process with his late partner, Charles Forbes, who was a Cal State Dominguez Hills professor.

“We were looking for an alternative to gas fumigation because so many people object to it,” Ebeling said. Heat is equally effective and can be used to treat an entire building or just a wall, he said.

Isolating a wall is useful for condominiums, where fumigating the whole structure would not be appropriate.

The method uses propane heaters that pump hot air into the tented house, where it is circulated by fans. To kill termites, the temperature must reach 120 degrees inside the wood, which means the temperature in the room would be 150 degrees, slightly less than the average sauna.

It takes about four or five hours to reach the needed temperature and maintain it long enough to break down the termites’ protective body coating. The heat is also fatal to other bugs.

Some items have to be removed or insulated against the heat, including candles, chocolate, computer equipment, medicine and thin plastics. Jedd Bennett, vice president of Isothermics, said applicators have to be careful to avoid getting direct heat on some surfaces, but the procedure shouldn’t damage the house.

Consumers can expect to pay about 10% to 30% more than fumigation, Bennett said, because it’s more labor-intensive; someone has to monitor heat levels during the procedure instead of being able to fumigate and leave.

Leading exterminating companies Orkin and Terminix said they are planning to add the method to their arsenal to accommodate customers who want a non-chemical alternative.

Bill Currie, a pest-management specialist with the U.S. Environmental Protection Agency, said the hot-air treatment looks promising so far, but he would like to investigate it further.

Researcher Rudolf Scheffrahn at the University of Florida said he remains skeptical of the heat method until he can see more scientific evidence that it’s effective in reaching every part of a house and doesn’t damage the structure.

At the other end of the non-chemical spectrum is the Blizzard System, which freezes termites. This method is done only by Long Beach-based Tallon Termite and Pest Control.

The company’s chief executive officer, Jay Tallon, says that in most cases, fumigation is overkill. Some exterminators use “scare tactics” to get homeowners to agree to fumigating the whole house when it isn’t necessary, he said.

An in-depth inspection that includes looking into walls with fiber-optic equipment can pinpoint termites accurately and allow an effective localized treatment, Tallon said. That’s sufficient in about 85% of cases, he said. The rest are houses so badly infested that it would be too expensive to use liquid nitrogen, so he recommends traditional fumigation.

Tallon got his start in the traditional pest control business and later switched to alternative approaches. His company introduced the Blizzard System in 1985, using a method developed by his brother, Joe Tallon Jr.

Tallon, known for its ads promising to “freeze their little buns off,” attacks termites by drilling small holes in the wall and pumping in liquid nitrogen, dropping the temperature to minus 20 degrees. The “termites turn to ice cubes,” the ads boast, and the holes are patched afterward.

Jay Tallon said the method is safe despite the December asphyxiation death of a Tallon worker who was not using a required oxygen monitor. Tallon is appealing safety violation citations by Cal/OSHA, the state workplace safety agency.

It’s safe for consumers because they aren’t allowed near the area being treated, Tallon said. The danger is that in a poorly ventilated area the nitrogen can displace oxygen, which apparently occurred to the suffocated worker, who was overcome in a closet. The nitrogen later warms and evaporates. The process takes from two to seven hours, he said.

Tallon also uses what it calls its Heat Wave system along with the freezing technique. Heated strips are placed on accessible wood to kill termites in those areas. For a 2,000-square-foot house, the cost is in the same range as fumigation, about $1,000 to $1,500, Jay Tallon said.

Termite expert Ebeling said he and Forbes did some research on freezing, finding it effective only in small areas. If a house is riddled with termites, he said, “you’d do more damage than the termites” by drilling and injecting liquid nitrogen.

It’s also unfeasible for large areas such as attics, where drywood termites often nest, he said.

Before Tallon launched the Blizzard System, it tried the Electro-Gun. The Electro-Gun, which resembles a large drill, has been in use for about 10 years, delivering lethal doses of electricity to the wood-eating pests.

“It can kill if you can get the electricity to the termite,” said Joe K. Mauldin, principal entomologist at the U.S. Southern Forest Experiment Station in Gulfport, Miss. That requires a skilled operator, said Loch Jones, a spokesman for ETEX LTD., which rents the Electro-Gun to pest-control operators and provides training. The electricity shoots down termite tunnels and kills the insects by breaking down their digestive systems.

While some exterminators said they had tried the gun and weren’t able to kill enough termites with it, Ebeling and others have found it successful as a spot treatment.

One Southland exterminator, Ecola Services, does traditional treatments, but also uses the gun when people are looking for an alternative, said Al Acevedo, Anaheim Hills branch manager. Minimum cost for a treatment is $820.

Jones said the gun is especially useful in museums, rest homes and hospitals where fumigation would be too disruptive.

Another spot treatment is a microwave-emitting device that, pointed at a wall, will cook termites inside in three minutes or less, said Stephen Roy of The Termite Inspector in Mission Hills. Average cost is $1,000. Roy said the area is sealed off for safety and doesn’t damage the wall. Like Tallon, he said the key is a good inspection to find the termites.

If exterminators are sure that drywood termites are only in a small area of the house, they can also drill and apply a localized chemical treatment, which costs about $150 to $250. The chemicals in the wall continue to kill any new termites that arrive in that area. Silica gels that dehydrate termites are also sometimes used as a preventive measure.

While fumigation, cold, heat, electricity and microwaves can kill drywood termites, there’s nothing left afterward to stop another bunch from swarming in next fall, as there is with the so-called “drill and fill” method of pesticide application.

WAYS TO DISCOURAGE TERMITES * Remove any wood, cardboard or paper from around the outside of your house. All contain termites’ favorite food, cellulose.

* Fix leaky pipes or faucets. They keep wood or soil underneath continually moist, which attracts termites.

* Check your landscaping. Wooden trellises and planters touching the house offer termites a bridge from soil to building.

* If you’re buying or building a new house, make sure the soil under your house is treated to make it unpleasant to termites. Check to see that the site is properly graded for good drainage. Wood sections of the house should not touch the soil, or should be chemically treated to resist termites. Consider hiring an inspector to make sure the house is free of termite-inviting conditions.

* If you’re buying a not-so-new house, have a termite inspection and do any needed repair work to prevent future termite guests.

* Inspect your house regularly for signs of termites or have a professional inspector do it. If you find termites before they’ve done much damage, it will be easier and cheaper to get rid of them.