Jennifer Root was told by a termite inspector some time ago that her 1923 Craftsman home in Eagle Rock was infested with the wood-gnawing pests.
The inspector recommended fumigationcovering the house with a tent and pumping in poisonous gasto eliminate the termites, but Root, 34, was nervous.
“I have a dog and two cats,” she said. “Tenting required us to be out of the house for three days, and I wanted an environmentally safe alternative that would be better for our health.
“I had heard of heat treatment and freezing but was so confused as to which methods actually work.”
Root, a publicist, agonized over the decision until August, when she finally had the wood in her home injected with a nonchemical insecticide made from orange-peel oil.
“I’m not sure how well it will work,” Root said, “but I’m relieved I finally got it done.”
When Root bought her house five years ago, she joined the ranks of the 60% to 80% of Southern California homeowners whose houses are infested with termites.
And because she bought her home in probate, Root had to accept it “as is,” termites and all. Most buyers and sellers, however, can’t close escrow without a report certifying that the home is termite-free. The report is not mandated by law, but most lenders require it before they will make a loan. (Root’s lender did not).
As a result, 1.2 million termite inspections were done statewide in 1998, according to Harvey Logan, executive vice president of the Pest Control Operators of California, an industry trade group.
“At least 90% of these inspections are the result of a real estate transaction,” said Donna Kingwell, executive officer of the California Structural Pest Control Board. And of those inspections, 95% show some evidence of termite infestation, either local or widespread, or a condition that could lead to a termite problem.
Booming right along with the strong real estate market is California’s termite population.
“As more people move,” said Vernard Lewis, an entomologist at UC Berkeley, “they bring belongings such as wood furniture and planter boxes containing termites. And as more homes are built, more wood is available for termites to feast on.”
With termites taking up residence just about everywhere, your home is a fertile feeding ground.
Homeowners’ insurance doesn’t cover termite damage, and eradicating the pests is expensive. Logan estimated that Californians spend about $1 billion on treatment each year.
The good news is that homeowners have an arsenal of alternative control methods, many of them nontoxic and greatly improved during the last several years.
“Concerned consumers have shown much interest in nonchemical methods of pest control,” said Eric Paulsen, technical director of the pest control trade group, “so the majority of companies now offer some sort of alternative.”
Those options include heating, zapping with microwaves, shocking with a device called the Electro-Gun, freezing with liquid nitrogen, even spraying with living fungi.
Companies offering these alternatives are reaping the benefits of catering to chemical-wary consumers. Jack Forster, president of Ecola Services, which specializes in alternative treatments, said his sales have increased 300% since 1991.
But do these methods really terminate termites?
Entomologists and pest-control operators say all the alternative methods, except heating, work best for treating small areas of infestation, such as a single wall or a room, not an entire house with extensive damage.
Before choosing a control method, you first need to know what kind of termite you’re taking on. California has two typesdrywood and subterraneanand it’s possible to have both at the same time.
Drywood termites, the most prevalent type in Southern California, especially in beach communities, live in attics, garages and the walls of your home, creating what termite experts call “galleries” (nests) in the wood.
They enter on sunny days, usually in late summer or fall, through vents, cracks, knotholes and exposed wood. When not infesting a home, termites can live in utility poles, dead trees and stored lumber.
Subterranean termites form nests in moist soil and tunnel underground to find wood, invading homes at cracks in the foundation or anywhere wood is in contact with soil.
Until recently, California has escaped the wrath of a particularly aggressive and destructive species of termite, the Formosan, found mainly in Hawaii and the Southeastern U.S. In 1992, entomologists discovered Formosans in a few homes in the San Diego suburb of La Mesa.
Michael Rust, a UC Riverside entomologist, said that although the Formosans aren’t headed our way yet, if the infestation spreads any further, “it could be a major problem.”
In the meantime, drywoods and subterraneans are causing enough damage. Despite the dominance of drywoods in Southern California, said Lewis, subterraneans are far more destructive, “so if you have subterranean termites, you might want to act more quickly.”
A little detective work is required to determine if you have an infestation. Termites rarely make their presence known because they devour their way through the wood’s interior rather than damage its exterior.
- Here’s what to look for:
- Swarms. Both drywood and subterranean termites form swarms to start new colonies, usually in spring or fall, especially near windows or lights.
- Piles of wings. Because termites shed their wings as they swarm, discarded wings are another indicator.
- Droppings. Drywood termites produce tiny hexagonal fecal pellets, often found in small piles in attics or below infested wood.
- Wood damage. Look for small holes in wood, crumbling drywall, sagging doors and loose window frames.
- Tubes. Subterranean termites create mud tubes about the diameter of a pencil on your home’s foundation. They use these tubes to move from the soil to your house without exposing themselves to the sun. Look for these tubes on the outside of your foundation.
When you suspect termite troubles, it’s time to call a professional pest control company to inspect the house.
After making a thorough visible check of your home, an inspector will outline where the termites are and recommend a course of treatment.
Inspection costs range from $50 to $150, although many companies offer them free.
Inspection methods are far from perfect, said UC Berkeley’s Lewis. “You could kill termites with anything if you could see them,” he said, “but inaccessible areas may exceed 45% of the total area searched during inspection.”
Currently, Lewis said, 99% of inspections are visual searches.
Much less common detection methods include fiber-optic scopes that look inside walls, acoustic emission devices (not yet available commercially) that listen for the sound of termites feeding and odor detectors sensitive to the gasses produced by termites.
Australian researchers, Lewis said, are experimenting with microwaves and lasers to detect termite movement.
Termite-sniffing dogs, beagles that can both hear and smell termites, are another less high-tech option.
“The problem with most of these methods is that you can only see a few feet of board at a time,” Lewis said.
Improving detection is key, he said, “because you need to know you have the right spot, especially for alternative treatments, which are applied locally.”
Even if termites aren’t chewing their way through your walls, the experts agree that you can save yourself from a potential takeover by getting yearly inspections.
“Your home should be inspected once a year,” Lewis said, “especially if it has a history of termite problems.”
Drywood Termite Control
According to experts, only two methods are effective for “whole-house” control of drywood termites: fumigation with gas or the application of heat.
Before Barbara Lewis bought her Sherman Oaks home in 1998, a routine termite inspection turned up 10 areas of infestation. The inspector suggested tenting.
“I was afraid of the gas and initially considered alternatives, but my real estate attorney and a geologist felt fumigation was a better option for getting all the termites out of the house and said it would kill other bugs too,” Lewis said.
She decided to have her house tented. “Everything went fine,” she said, “and I am glad the whole house is bug- and termite-free.”
Because drywood termites are so difficult to find, fumigation, which penetrates every area of the structure, is the best way to eradicate them completely, said Kingwell, of the state Structural Pest Control Board.
In 1998, about 55,441 fumigations were done in Los Angeles County, 21,990 in Orange County and 39,000 in San Bernardino County, according to the Los Angeles County agricultural commissioner.
Kingwell said 95% of fumigations in California use sulfuryl fluoride (trade name Vikane), and 5% use methyl bromide.
Vikane is an odorless nonflammable gas that kills termites by preventing them from metabolizing stored fats.
For many years, methyl bromide was the fumigant of choice because it was cheaper than Vikane. But beginning in 1993, compliance with added state regulations made methyl bromide less cost-effective, and its use dropped dramatically.
The U.S. Environmental Protection Agency, acting on concerns about methyl bromide’s effects on humans and the environment, ordered the gas phased out of production by 2005.
Michael Mornic, regional manager for Orkin Pest Control, said companies now use methyl bromide only when a house will be vacant for long periods of time, because it takes longer to aerate the structure than with Vikane, and because the gas tends to react with rubber, furs and other materials.
Before a whole-house fumigation is done, plants and animals must be removed. Anything that can be consumed, including medications, needs to be taken out unless it is sealed in glass or metal containers or left double-bagged in plastic bags supplied by the pest-control company.
Vikane leaves no residue, so leather, dishes and utensils do not need extra protection. It can, however, penetrate anything with a plastic cover, such as a baby mattress or a garment bag.
Other preparations include watering the soil around the house the night before and cutting back any vegetation next to the house.
The fumigator seals off the house using nylon tarps clipped together with metal clamps. The home can also be sealed with plastic, tape or other materials. Special locks are placed on the doorknobs to keep out intruders.
“You can’t perfectly seal off a structure because of its size,” Mornic said. “There will be some gas loss, but it’s not harmful because of the small quantity.” Even if the tarp blew off, he said, "[the gas] would just dissipate into the atmosphere.”
To determine the necessary dose of gas, the fumigator uses a special calculator that takes into account the size of the home and environmental conditions.
Before the gas is pumped in, the house is thoroughly searched, then an odorous tear gas is released as a warning to any people or pets that might still be inside.
Fans distribute the Vikane throughout the house, where it penetrates the walls and termites breathe it in.
Fumigation takes about 12 to 24 hours. After the tarp is removed, the home must be aerated for a minimum of six hours. The fumigator then uses a scanning device to check places where gas could possibly accumulate (dishwashers and closets are common spots).
When the detectable gas levels are below 5 parts per million, it is safe to reenter. The total time out for homeowners is two to three days.
Fumigation killed 100% of the termites in a 1996 study of six treatment methods at UC Berkeley. (See accompanying story.)
The cost of fumigation ranges from $700 to $2,000, depending on the size of the structure and the amount of gas used.
Heat, or “thermagation,” is the only alternative to whole-house fumigation and can also be used as a local treatment.
Termites cannot tolerate high heat because “they don’t have the ability to sweat,” explained Dave Lawson, technical director for TPE Associates, which licenses the Thermo Pest Eradication technology to 20 companies in California.
For whole-house thermagation, a tarp is draped around the sides of the home but not on the roof. Specialized propane heaters set up outside the house generate heat on the exterior walls and on the inside through portable duct systems.
The temperature inside the house reaches 140 to 150 degrees Fahrenheit, “about the same as an auto on a hot day,” said Lawson. The pest-control operator inserts thin wire probes into the wood to monitor the temperature, which must be held at 120 degrees for at least 30 minutes to kill the termites.
Lawson said the whole thermagation takes about four to six hours.
Homeowners must remove any items they wouldn’t leave on a car dashboard on a warm day, including lipstick, tapes and CDs, candy bars and computer disks.
Fresh fruits and vegetables will wilt if left out, but refrigerators can remain on. Pianos, antique furniture and other items too large to move are covered with special thermal blankets to keep them cool.
A side benefit to heating, said Lawson, is that it removes odors, such as cigarette smoke, as well as killing bacteria, fungus and other bugs.
For local treatment, the heat is applied to one room at a time, and homeowners can remain in the house.
In the Berkeley study, heating killed 96% of the termites after three days, 98% after four weeks.
The researchers also found that the heat caused some wood damage: minor warping of boards and sticking doors.
Lawson said that “these problems have become less over the last few years as technology has improved. More training has made a major difference.”
Cost: about $700 to $1,500 for local treatment. For whole-house thermagation, expect to pay about 20% to 30% more than for fumigation because heating is more labor-intensive.
According to Paulsen, of the pest control operators trade group, most treatments for drywood termites in California are local or spot applications using chemical pesticides (70%) or fumigation (22%) or alternative methods (8%).
A downside to most methods of drywood termite control, including heat and fumigation, is that they don’t have any residual effect, meaning that another infestation is possible even the next day.
The only way to keep termites out is to treat the wood with liquid insecticides that have a long-lasting repellent effect.
To eliminate drywood termites in areas with unfinished exposed wood, including garages, attics, window casings and decks, pest-control companies can spray or inject the wood with borates or other chemical insecticides or with a silica aerogel.
In painted areas or inside walls, technicians can drill holes and inject the same products (if they know the exact location of the termites).
Borates like Tim-Bor and Bora-Care, the pesticides most companies use to beat back drywood termites, act as both stomach poisons and protective barriers.
“They’re low in toxicity and can last almost the life of the wood,” said Orkin’s Mornic, “although they are slow-acting, so the termites don’t die right away.”
Borates are becoming more popular as companies use them in conjunction with alternative treatments to provide more complete protection.
Silica aerogel, a dust often combined with a low-toxicity pesticide, is applied mainly in attics and other confined areas. It either poisons termites or destroys their protective body coverings, causing them to dry out.
Less widely used for local wood treatment are such toxic chemical termiticides as chlorpyrifos and pyrethroids. (See accompanying article for descriptions of these chemicals and the controversy over their safety.)
A nonchemical option is Power Plant, the liquid insecticide used to treat Root’s home. Its active ingredient is limonene, an oil from orange peels, which kills termites instantly by drying out their waxy skeletons. It even leaves a pleasant orange smell.
The product is still relatively new, said Al Maddox of Tallon Termite and Pest Control, although industry word-of-mouth has made its use more widespread.
Borates have been shown in studies to be effective for 30 years or longer, but little research has been done on other liquid pesticides.
Cost for any liquid treatment: $200 to $2,000.
The high-voltage, high-frequency Electro-Gun, developed in 1979, looks like a sci-fi ray gun with a cord. Phil Holt, president of Etex, a Las Vegas-based company that leases the gun to pest control companies, said 19 companies in California use the device.
The gun’s 90,000-volt electric current penetrates wood and kills termites by shocking them. The termites die instantly or within two to six weeks, depending on the strength of the shock they receive.
The device works best when the technician drills holes in the wood, then inserts a wire pin to channel the electricity. The wood doesn’t burn because the current comes out in pulses, not in a steady flow, and the temperature in the wood rises only 15 to 20 degrees.
The gun is safe for the operator and anyone nearby because high-frequency electricity does not penetrate human skin.
Before treatment, all electronic items must be disconnected, such as alarm systems and computer modems, “anything with a wire that might get hit,” said Holt. Utility wires are not affected.
The procedure can take from several hours to one day.
The Electro-Gun will not work if you have a widespread infestation and is not feasible if you have lots of wiring and electronics. Holt said that if the initial inspection found an infestation near metal or concrete, which can attract the current away from the termites, the company would recommend another method.
In the Villa Termiti study, the Electro-Gun killed 93% of termites after three days, 99% after four weeks. In 1997, Australian researchers found the device to be 100% effective.
Troy Sears, president of Coast Termite and Pest Control, which offers all the alternative treatments including the Electro-Gun, said he is considering returning the device to Etex.
“It kills a limited amount of termites and only works when it’s backed up by [the borate] Tim-Bor.”
The failure rate depends on the skill of the applicator, Holt said, and the company does recommend using borates for long-term prevention.
Over the last three years, added Holt, skills and technology have improved. “We’ve upped the voltage so that it is better able to penetrate thick wood, and we’re better at directing the current.”
Cost: $75 to $1,500, depending on the number of areas treated.
The termite-killing microwave generator operates on the same principles as your kitchen microwave oven.
About the size of two shoe boxes, the device is aimed at an infested area and activated by a remote control on a 30-foot cord. It kills termites through the walls by bombarding them with microwaves.
“It’s best used for small spot treatmentsdoors, walls and window frames,” said Ted Verdun, an inspector with Coast Termite and Pest Control, Santa Ana. “It’s somewhat limited. You can’t treat an attic or any sub-areas of the house.”
Treatment time ranges from two hours to a full day.
The microwave can scorch boards, although any damage to the walls that occurs, Verdun said, is usually a result of technical errors. “Heating is a better method,” he added, “but only a few companies offer it, while many offer microwave technology.”
The microwave is not harmful to people, as long as they stay 30 feet from the device. “Getting any closer could cause soft-tissue damage to eyes and sterility in men,” said Verdun.
UC Berkeley’s Villa Termiti study found that microwaves killed 90% of termites after three days, 92% after four weeks.
Cost: $200 to $2,000.
“Freeze their little buns off” announce the ads for Tallon Termite and Pest Control, the only company in the United States to offer the “Blizzard System,” which uses liquid nitrogen to kill termites.
The pest-control operator uses a fiber-optic scope to look in the wall, then drills holes about the size of a dime to apply liquid nitrogen under pressure to the wall area.
The nitrogen is stored in tanks at 350 degrees below zero Fahrenheit until it is injected into the walls, where it cools the area to 20 degrees below zero Fahrenheit. Because termites are 90% water, the nitrogen freezes them and they burst.
For areas around moldings or windows, said Jay Tallon, president and CEO of Tallon Termite and Pest Control, the operator uses special heat strips instead because nitrogen can crack glass.
People can remain in the home during application, but not in the immediate area. Although nitrogen is not toxicit makes up 80% of the air we breathethe pest-control operator must take care to ventilate enclosed spaces, because if too much nitrogen is released, it can rob the air of oxygen.
Treatment time ranges from 30 minutes to a full day, depending on how heavy the infestation is.
Steve Griffith, who lives in a 30-unit three-story condominium complex in Redondo Beach, convinced his homeowners’ association to try liquid nitrogen on the building six months ago.
“We have elderly people and lots of cats and dogs here,” said Griffith. “This was nontoxic, and we didn’t have to pack up and leave home. It only took a day and a half. The company has monitored it every month, and the termites haven’t come back.”
Liquid nitrogen killed 100% of the termites in the Villa Termiti study. Tallon, however, said the researchers “used a ridiculously high amount.”
A more accurate figure, Tallon said, is the company’s 5% call-back rate to retreat a structure. “And re-treatment usually results from human error,” he said, “not the process itself.”
The procedure also leaves holes in walls, but Tallon said these are small and that the company will patch the area.
Liquid nitrogen treatment costs about the same as fumigation, and if a home has a severe infestation, the company recommends fumigation.
Before granting registration to a pesticide, the state requires extensive tests of safety and effectiveness.
“‘This is a major problem, because there’s a lot of fraud in our industry,” said Sears of Coast Termite and Pest Control. “Companies play on consumers’ need for less-toxic treatment with products that don’t work.”
Pest-killing devices will soon be held to the same standards as pesticides, however.
According to Veda Federighi, a spokesperson for the state Department of Pesticide Regulation, a bill that took effect at the beginning of this year requires the agency to establish a regulation program for structural pest-control devices, including heat technology, microwaves and the Electro-Gun.
The devices must be registered by July 2001. “Applicants will have to show that the devices are both safe and effective,” said Federighi.
Subterranean Termite Control
Since the 1940s, liquid termiticides have been the dominant form of subterranean termite control. The chemicals are applied to soil around foundation walls, in crawl spaces or beneath concrete slabs, creating a poisonous barrier that repels termites.
All termiticides for subterranean termites, marketed under such trade names as Dragnet and Demon, have the same seven active ingredients, according to Brad Kard, principal research entomologist with the U.S. Forest Service at Mississippi State University.
The pest control operator will suggest which termiticide to use based on soil conditions and your preferences, said Mornic of Orkin Pest Control. For example, if you’re concerned about smell, the operator might use Premise, which is odorless.
The chemicals are applied in a depression in the soil 4 to 6 inches wide and deep around your home. The pest control operator fills the trench with the chemical, then places the soil back on top. If the house sits on a concrete slab foundation, the pest control operator can drill a series of vertical holes in the slab or drill horizontally through foundation walls to inject the termiticide into the soil.
“The chemical is highly diluted,” Kard said. “The concentration of active ingredients is usually .05% to 1%.” Most dangers are to the applicators because they deal with the concentrate.
Kard explained that “the chemicals are designed to stay in the soil, not leach out. They’re not water-soluble; they are mixed in water but don’t dissolve in it.”
If a pond or stream is within 20 feet of your home, the pest-control operator should check for the possibility of contamination, which could occur only if the termiticide was injected straight into the water.
Kard, who is in charge of testing all termiticides submitted to the EPA for registration, said the chemicals must be 100% successful in keeping subterranean termites from penetrating various barriers for a minimum of five years before they are approved.
Today’s termiticides are less toxic because they break down more quickly. The drawback: Because most last only about seven years, you’ll need to reapply the chemical regularly.
Cost: about $7 per linear foot of foundation.
Although the goal of chemical pesticides is to create a continuous barrier, termites can tunnel through a gap in the soil as narrow as a pencil lead. Baits, introduced in 1995, kill termites rather than create a barrier.
The active ingredient in Sentricon, the first commercial bait system, is hexaflumoron, which prevents termites from molting.
The ingredients in two other baits, FirstLine and Subterfuge, act as respiratory inhibitors.
All three have extremely low toxicity and are used in such small amounts that they pose little risk to humans. “If you want to avoid termiticides, definitely go this route,” said Paulsen, of the pest control trade group.
Because the baits are slow-acting, they can destroy an entire colony. Before dying, the termites that ingest the bait have time to return to their nests, where they dole it out to their unsuspecting peers.
Baiting requires careful monitoring by a pest-control company. Plastic bait stations (they look like sprinklers) containing a piece of wood are placed in the ground at fixed intervals around the house or near places of suspected termite activity.
The pest-control operator returns monthly to see if termites are attracted to the wood, then adds the bait. When no more termite activity is seen, the colony is considered eliminated, although it’s impossible to know for sure. The pest control operator must return every few months to monitor activity.
The devices can also be installed above ground, usually in a door frame or on a home’s foundation in the path of a mud tube.
The drawback to baiting is that termites can take as long as a few weeks or even a year to find the bait.
“You have to decide if the advantage of not putting chemicals in the soil outweighs the advantage of immediate control,” said Greg Baumann, director of technical and field services for the National Pest Control Assn.
The long wait might especially be a problem if you’re trying to close escrow and need a quick termite fix.
Researchers are working on ways to speed up the process. Lou Bjostad, a professor of entomology at Colorado State University, and his colleagues Elisa Bernklau, Erich Fromm and Greg Walker, have had success using carbon dioxide to lure termites to baits.
“Termites are attracted to 1% carbon dioxide, which is about 10 times the concentration in the air,” he said. His studies have shown that it takes termites only about one week to arrive at traps baited with carbon dioxide-generating formulations.
Carbon dioxide is not yet available for commercial use, said Bjostad, whose research will be completed in October.
Studies on baits are lacking, and EPA standards for baits are different from the five-year effectiveness rate required for termiticides.
“Now, a bait only has to demonstrate in field tests that it has eliminated or greatly reduced colonies,” said Kard, a member of the EPA committee on baits. “We’re looking at putting out stronger guidelines about how they are expected to perform,” he said.
Baiting is also labor-intensive because of the monitoring requirements, although technological improvements might lessen the load.
According to Nan-Yao Su, a professor of entomology at the University of Florida, “We’re trying to automate the system, possibly by putting an electronic sensor in the trap.”
Orkin’s Mornic doesn’t recommend baits as a stand-alone treatment. “The best of both worlds,” he said, “is to take care of immediate problems with chemicals and use baits to suppress the colony.”
Cost: around $2,000, plus monitoring fees (about $50 per month).
Add nematodes to the eclectic array of nonchemical termite killers.
Nematodes, available for pest control since the early 1980s, are microscopic roundworms that are mixed with water and injected into the soil.
According to Albert Pye, an entomologist and president of BioLogic, a Pennsylvania company that supplies nematodes, the worms enter the termites through natural body openings and penetrate into their bodies, causing physical damage when they grow.
Although you can buy nematodes yourself, Pye recommended people use a professional service because “application techniques are important.”
“We’ve had limited success [in testing nematodes],” said Kard of the U.S. Forest Service. I don’t recommend them either way because although they do kill termites, we don’t have any scientific evidence they can control entire termite infestations.”
Cost: $56.55 for the first pint, $35 for each additional pint. (One pint treats 40 linear feet of foundation.)
One nonchemical product on the market kills both subterranean and drywood termites. BioBlast, a fungus found naturally in the soil, penetrates the termites’ skin and, like a bomb, releases deadly spores.
BioBlast comes in a powder form that is mixed with water. It must be applied directly to the termites, which means you have to know exactly where an infestation is. The termites take several days to die.
It is applied by drilling a hole in wood and spraying it directly on the termites, or outside into mud tubes. BioBlast does not work in the soil, although once termites are doused with the stuff, they carry the spores back to their nests, leading to elimination of the entire colony.
In field tests, said Kard, termites showed “lots of mortality,” but he recommended using BioBlast with a chemical termiticide because it lasts only about three to five months.
Cost: $129.95 for a box of three packets. One packet will treat a whole house, the manufacturers say.
* * *