Coming to Terms with Termites

If we could make a window into the subterranean environment, we would see a world as intricate and alive as what we know above ground. This is the domain of one of our most common household pests, the Desert Subterranean Termite. In the wild, all termites play an important role helping to break down dead plant material and dung, insuring that nutrients are recycled back into the soil. Their tunnels help to circulate air and water in the soils, which is necessary for healthy plant growth. They are also an abundant source of food for lizards, birds and larger insects. In some African and Indonesian cultures, termites are a common snack for people too, usually served roasted and lightly salted. Yum!

More than 2600 species of termites are known around the world; less than 10% of those cause damage to buildings. In the U.S. we have forty-five species; eighteen are found in Arizona, but only four of those species commonly become pests when they feed on man-made structures. Of these, the Desert Subterranean Termite (Heterotermes aureus) is the most pervasive native termite of the Mojave and Sonoran Deserts in California, Arizona and Mexico.

Like ants and honeybees, termites are colonial, with several functional roles or "castes." Each colony begins with a queen and king, who are responsible for mating and producing eggs. Although a newly mated pair needs to care for their first set of offspring on their own, eventually they produce thousands of workers whose duties include feeding and grooming the royal couple, as well as eggs, larvae and each other. The tiny quarter-inch long workers cooperate to build extensive tunnel and gallery systems that reach as far as three meters below the surface and may house up to 300,000 termites. About 10% of a colony develops into sterile soldiers equipped with fierce jaws that can crush other insects, especially ants, that may invade a colony.

During evenings in late summer months, you may notice winged termites, also known as "alates," swarming outside, or if you are unlucky, inside your home. These termites, unlike workers and soldiers, are able to mate and reproduce. If a male and female find each other and a suitable place to burrow into the soil, they will start a new colony. Thousands of alates will swarm from a mature colony each year, but only a few escape the fate of death by predation or other natural causes.

Termites are dependent on specialized bacteria, fungi and protozoans in their gut that are able to digest wood. By sharing food with the rest of the colony, workers also transfer gut organisms to new larvae and each other. This behavior is one way that toxins used for termite control get distributed. Any termite that encounters the toxin will return to the colony, where mutual feeding and grooming will cause the poison to spread throughout the population. It normally takes just a few days for an entire colony to be infected with the toxin and die.

Either you've had them in your home, or you will, but if you can suspend your horror and disgust at the idea of tiny bugs munching away inside your walls, the world of termites is actually quite fascinating. Despite their potentially destructive impact to our homes, termites are critical to the health of our desert ecosystem. You can do your part to reduce the introduction of toxins
necessary to destroy them by creating termite resistant physical and chemical barriers to your house. This way, termites will carry on in their important ecological role in the desert around, but not inside, your home. Some ways you can minimize the likelihood of termites entering your house include:

*Make sure there is no yummy termite food next to your house, which includes any kind of wood, whether it is firewood, crates, building materials or furniture.
*Keep areas next to the house dry and free of irrigation. Termites prefer to forage in moist soils.
*Be sure that floor joints and cracks are sealed and treated with termite repellant before you install wood flooring.
*Do regular inspections around your foundation and interior walls to catch any termite activity before it creates serious damage. Call a certified professional to chemically treat any problems.

For more detailed information on local termite ecology and control, check out the Arizona Cooperative Extension document: Arizona Termites of Economic Importance (2005).

Note
If you are buying or selling a house in Arizona, it is customary for the seller to be responsible for any termite protection that is deemed necessary before closing on a real estate contract. Usually this involves an inspection and a treatment that includes a minimum one-year warranty if any active termites are found.