ENVIRONMENT HEALTH COALITION
http://www.environmentalhealth.org/fs-termite.html
Alternatives to Toxic
Termite Control, January, 2002
Environmental Health Coalition does not endorse any products or
services. Although we have made every effort to verify that the information is
complete and current, there may be additional alternatives or companies that we
have inadvertently left out.
When Do You Need
Termite Treatment?
According to the Northwest Coalition for Alternatives to Pesticides, a large drywood colony consumes about half a pound of wood per year, and it takes seven years for a colony to develop to this size.1 This means you have time to evaluate options for prevention and treatment before taking action. This fact sheet includes a summary of termite eradication options as well as prevention options. EHC always recommends prevention as the first and foremost approach to dealing with any pest problem. However, if you are a tenant or a condo dweller, you may be in a situation where someone else is proposing to fumigate your home. In this case, the termite eradication alternatives may be the information you need immediately for avoiding fumigation.
Prevention
Drywood Termites
First, seal termites out. Cover exposed wood with paint or sealer. Caulk cracks and crevices. Screen windows and vents.
Second, treatment of exposed wood with borates or boric acid provides long term protection against infestation.
Subterranean Termites
Don’t have wood in contact with soil.
Cover exposed wood with paint or sealer.
Remove wood debris from your yard.
Plant trees away from house, and prune away vegetation that provides
a bridge to the house.
Ants are predators of termites. Do not kill ants that are not causing a nuisance
problem in the house.
Treatment Options
According to Sheila Daar and William and Helga Olkowski, " The most permanent, most effective
and safest treatment of the problem at the most reasonable cost may require a careful integration of activities carried out by the homeowner and a number of experienced professionals [ such as carpenters] from more than one company." These are the nontoxic or least-toxic options that may be incorporated into your strategy:
Removal or repair of infested wood. For a small infestation, this may be all that
is needed.
Heat: This
involves tenting and heating either the whole
structure or just a part of it up to 140 degrees Fo, a temperature
that will not harm the structure. A test of termite eradication methods at UC
Berkeley in 1996 resulted in a 100% mortality of termites in naturally infested
wood boards treated with heat.3 Care is required to remove all
household items that may be damaged by heat, such as electronic equipment.
Microwaves: this is a spot treatment method that
also kills the termites by applying heat. The researchers cited above got a
100% mortality rate with this method as well, applied to naturally infested
boards. Other studies have had varying success rates. House damage may include
warped wood and wood burns.
Cold: cold treatment with liquid nitrogen is a spot treatment method whose effectiveness ranged from 74 to 100% in the above tests, depending on the dose used. This can be an effective method for inaccessible areas, as nitrogen is injected through small holes drilled into the walls. Frost formation within the house may damage some wall coverings. Drill holes must be repaired.
Electrocution: Called Electrogun, this is a spot treatment using volts of electricity, which kills termites in exposed wood. Mortality in the above tests was 95% four weeks after treatment in naturally infested wood. Drill holes and minor wood burns may result from the Electrogun method.
Borates: Borate salts or boric acid can be injected into wood as a treatment or applied to wood surfaces as a preventive measure. Borate dust may be used in wall voids as well. Borate foam is another form of borate that may be applied as a spot treatment. Depending on the product and treatment method, borates may act as a contact poison or a stomach poison. Borates should not be used on wood in contact with soil, as they are water soluble and will leach into the soil. Tim-Bor, Bora-Care, Jecta, and Impel are some brand names of borate products. Ethylene glycol may be added to liquid formulations of borates; this substance increases the penetration of the borate into wood but may be a problem for chemically sensitive individuals.
Fungal pathogens: BioBlast is the trade name of a method that utilizes a fungus that is deadly for termites when sprayed onto the infested wood.
Limonene or other citrus derivatives. Limonene has been used successfully as a pet flea control agent, and is now being applied to termite control. No information was found regarding the effectiveness of this method, whether it provides residual protection, or to what extent it is found in the indoor air of structures treated with it.
Neither borates nor fungal pathogens was tested in the Lewis-Haverty study cited above, so their effectiveness cannot be directly compared to the other drywood termite treatment methods. Both of them provide some residual protection against reinfestations, whereas fumigation, heat, cold, and Electrogun do not.
Subterranean termites
Pyrethrins: pyrethrins are less acutely toxic (poisonous) than Vikane or Dursban, and they break down quickly when exposed to sunlight, so they are not persistent toxins. However, recent research has suggested that pyrethrins have hormone disrupting properties that raise concerns about human exposure to them.
Nematodes: certain species of nematodes attack insects rather than plant roots and can be used for subterranean termite control.
Sentricon/Recruit II is a Dow Agrosciences product that consists of a termite bait containing an insect growth regulator, hexaflumuron. The product is designed to used as part of an integrated pest management system and sold as a service, not over the counter. Hexaflumuron can cause irritation to eyes or skin but had low toxicity to rats who ate it or breathed it in laboratory studies. It is highly toxic to aquatic life and should not be used in low areas or near water sources.
Termidor is another relatively new product for subterranean termite control, to be used only by licensed termite exterminators. It contains fipronil, a phenyl pyrazole type of pesticide that kills by disrupting nerve transmission. It is irritating to eyes and skin, and is toxic by all routes of exposure (skin contact, breathing, ingestion). The acute toxicity of fipronil is moderately high, based on lab rat studies. Chronic toxicity studies show it is harmful to the nervous systems of both rats and dogs. It is classified by the United States Environmental Protection Agency as a possible human carcinogen based on thyroid tumors in rat studies. It is toxic to aquatic wildlife and should not be used in low areas or near water sources.
For more
information, or to share your own concerns, problems, comments, questions,
contact:
Toxics
Information Project (TIP),
Tel. 401-351-9193, E-Mail: TIP@toxicsinfo.org Website:
www.toxicsinfo.org