Q: I am about to build a house with my husband, and it seems the only way to prevent termites is to treat the foundation/soil with chemicals. Is there a greener way that is proven effective? —Jenny Chua-Medina
A: Along with scary postcards from exterminators that arrive with warmer weather, your question reminds me that termite attack season is upon us. Happily, yes, there are greener ways than chemical treatments to control termites. And your timing is perfect: The ideal window for taking preventive measures is while you’re building a house, says Alan Cohen, president of Bio-Logical Pest Management and a former board member of Beyond Pesticides, a non-profit organization that provides resources on least-toxic pest control.
But first, take a deep breath. Whether you’re building new or dealing with an existing home, it’s important not to panic over termites, advises Stephanie Davio, public education associate for Beyond Pesticides. Despite widespread fears of structural damage that might be incurred by ground (subterranean) termites, “It takes a lot longer than people think. They’re not going to come and destroy your house overnight,” Davio says. The goal, she says, should not be total eradication so much as to “keep the populations low and in check.”
A History of Toxic Chemicals
In the bad old days, subterranean termites were routinely dealt with by injecting chemical pesticides into the ground. The most widely used termite killer, chlordane, was banned in 1988 because it was linked to cancers and persisted in the environment, accumulating in people’s body fat, for 20-plus years. Chlorpyrifos (Dursban), commonly aimed at cockroaches as well as termites, was banned for residential and school uses in 2001 (PDF: http://www.beyondpesticides.org/news/pressreleases/Dursban_1.pdf)
Least-Toxic Termite Management
For starts, seek information from state agencies and professional guidance from a green termite control specialist. Click on your state in Beyond Pesticides’ Safety Sources for Pest Management map.
Know Thy Pest
First, take a look at the critters to identify what kind of termites you’ve got, Davio says, noting that there are dry wood, subterranean and damp wood types. A lot also depends on where you live and your climate. Use Beyond Pesticides’ descriptive Termite Fact Sheet. (PDF: http://www.beyondpesticides.org/alternatives/factsheets/Termite%20Control.pdf)
When building new or renovating, Cohen recommends using termite-resistant materials. “You can do pretreatment of wood with least-toxic boric acid, found in products such as Bora Care,” he says. “CC (copper chromate) can still be used, but the ‘A’ [as in CCA], for arsenic, is gone,” since Beyond Pesticides sued EPA to ban it, Cohen explains. That’s definitely a relief, since arsenic is a potent poison that can rub off on children’s hands (which is why it was banned) and leach into soil and water, being taken up by plants, including food crops.
Termite barriers made of rock particles and stainless steel mesh can be installed before pouring foundations and around posts.
Existing Homes: Baits and Heat Treatments
If you’re living in a house with telltale signs of termites (crawlers, flyers, droppings) and damage (holes in walls, floors and beams), get a comprehensive professional inspection “to see what’s going on and talk about termite conducive factors,” Cohen advises.
Termite conducive factors include moisture and rotting wood. To prevent infestations, “Keep water away from the foundation, that’s 90 percent of it,” Cohen says. “Clean gutters out, keep landscaping a bit away from the foundation so it has a chance to dry out and gives you a chance to inspect better,” he adds.
Nowadays, conventional home tenting operations use the pesticide Termidor (fipronil), which “is less toxic [than chlorpyrifos] but still a neurotoxin,” Cohen says.
In the event of a general infestation (which is rare), rather than tenting with toxic chemicals, tenting with heat is just as effective, Cohen says. Do be direct with so-called green professionals. “You have to hold their feet to the fire and ask what they mean by green. Ask if they can tent with heat.”
Cohen’s preferred green method is to use bait stations, which are wood or cellulose inside a plastic housing “that can’t be opened except with a special tool, so it’s child and pet resistant,” he says. But you or your pest control professional should open and inspect them regularly.
How baits work: Because termite workers are blind, and attracted by wood fiber baits, they stumble into stations placed throughout the home. Once you find them inside, you add a growth-inhibiting chemical. “The workers carry it back and it hurts the juveniles. Eventually it kills the queen,” Cohen says.
In other words, it’s the Trojan horse in miniature, with a little bit of Jacobean drama thrown in. Who knew terminating termites could involve such intrigue?
A chiton inhibitor, Davio explains, prevents the growth of a new outer shell once the insect has moulted and outgrown its old one. Boric acid does the same thing, as does diatomaceous earth, she says. Either can be applied to termite nests, and, if you want something that smells sweet to you but not to pests, try plan essential oils such as rosemary, peppermint or lavender, which are “also poisonous to termites (although the research is still very new regarding their efficacy),” Davio adds.
And here’s the best part: If, after roaming through Beyond Pesticides’ wonderfully helpful and detailed web pages, you still have specific pest control questions, Davio will personally answer them to the best of her ability and organizational resources. You can reach her at firstname.lastname@example.org.
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