We wrote last Sunday about the devastating effect that termites can have on a home, and various precautions that can be taken to discourage them from making your home their home. Now we'll examine what to do when they already are feasting on your domicile.
Having your house inspected by a professional is a good investment. In fact, the few hundred dollars spent on an average inspection can save thousands of dollars in repairs.
An inspection and report can be quite complicated. For this reason we recommend that a consumer get two reports and make comparisons. Chances are that while many of the items will be consistent, there might be items that one inspector misses that require attention. The additional cost of a second report is good insurance and can save money in the long run.
Traditional termite treatment has involved highly toxic chemicals. Most chemicals used by the pest control industry fall into three categories: soil termiticides, fumigants and fungicides.
Soil termiticides are used primarily to treat subterranean termites. Termiticides used to consist of chlorinated hydrocarbons like chlordane and DDT, many of which are now banned because of their high level of toxicity. A less toxic alternative to the chlorinated hydrocarbons is chlorpyrifos or Dursban. Metoprene, an insect juvenile hormone that prevents termite nymphs from maturing into reproductive adults, is a less toxic alternative.
Drywood termites have traditionally been dealt with using highly toxic fumigants such as sulfuryl flouride and methyl bromide. The entire building is tented and the fumigants are introduced throughout. The vapors are so potent that residents are required to vacate for at least two days.
Fungicides are applied to wood to prevent fungus infections. Pressure-treated wood, available at the lumberyard, is soaked in a pesticide (arsenic or creosote products) under pressure to make the material more rot-resistant and hence less attractive to termites.
Because there are health hazards from the toxicity of pressure-treated wood, a better alternative is to treat your own wood by soaking it in a less toxic preservative. Copper naphthenate, copper-8-quinolinate and zinc naphthenate are a few of the preservative formulas that can be found in commercial products that the U.S. Forest Service lists as less toxic than most others on the market.
An assortment of least-toxic alternatives to traditional forms of toxic pest control have become more popular. While many pest control operators dismiss these alternatives as ineffective, consumer concerns are causing the industry to look at them.
A new approach to killing drywood termites involves a new tool called an "Electrogun." It electrocutes termites using low current (90 watts), high voltage (90,000 volts) and high frequency (100 kHz).
If using electricity shocks you, freezing termites is an alternative. The termites die when liquid nitrogen, pumped into the affected areas, drops the temperature of the wood framing to about 20-degrees below zero Fahrenheit. The entire process takes a few hours and, unlike fumigants, does not require tenting.
While the liquid nitrogen technique is less toxic, there are hazards. This method should be undertaken by a professional.
If freezing gives you the chills, you might consider baking the pests. This method converts the entire structure to an oven. Propane heaters are used to blow hot air into a tented house to create temperatures that are lethal to termites. The ambient temperature of the space is brought up to about 150 degrees Fahrenheit with the specific temperature of the wood framing at about 120 degrees Fahrenheit.
The heat treatment can be performed in a matter of a few hours. However, it requires the tenting of the house, and can damage fine furniture, electronics and products made from plastics.
There are some biological controls for termites as well. Ants, for example, are among the most important enemies of termites. Argentine ants have been known to kill termites overnight. While you may not want to have ants crawling along your kitchen counters or under your sink, with proper management you can keep them out of the house or contain them in the crawl space for natural termite control.
Where pesticides are routinely applied at the perimeter of foundations to prevent ant invasion into the building, the beneficial effects of ant predation against termites will be lost. Instead of using ant sprays, consider using an insecticidal soap, a spray solution of soap and water or boric acid at the location where ants enter the home. Each of these is nontoxic and will prevent ants from coming into the home, but will allow them to prosper outside it.
Desiccating dusts head the list of least toxic materials to use against drywood termites. These dusts include amorphous diatomaceous earth (not the swimming pool kind) and amorphous silica aerogels.
These dusts either abrade or absorb the waxy layer on the outer coat of insect bodies, causing them to dehydrate and die from excessive moisture loss.
Finally, there are nematodes, microscopic worms that feed on subterranean termites. Marketed as Spear, the commercial product is a mix of predatory nematodes and is applied to infested wood or soil in a water solution much like a commercial termiticide.
The nematodes seek out termites over short distances--at most a few inches--enter their bodies and kill them. Since individual termites eat dead and dying termites, and share food and feces, the nematodes spread rapidly throughout a termite colony and destroy part or all of it.
Unlike the long-lived pesticides, the nematodes live a maximum of two years, depending on moisture conditions. Nematodes cannot survive desiccation. Thus, after they have killed the termites, they die relatively quickly.
For additional information on the least-toxic methods for managing pests, contact Bio-Integral Resource Center (BIRC), P.O. Box 7414, Berkeley, Calif. 94707, (510) 524-2567.
Our thanks to the folks at BIRC for providing information contained in this column.