Desert Subterranean Termites

Area of Distribution: The Desert subterranean termite is almost entirely restricted to the Colorado and Gila deserts of southern Arizona and California and into Lower Baja California and it occurs occasionally in Houston, Texas.

The Desert subterranean termite is one of the most common subterranean termites in Arizona.

The Desert subterranean termite lives in desert plants including dead cactus, but can severely damage structural timbers in buildings, utility poles and other timber structures.

Identification of Swarmers and Soldiers: The Desert subterranean termite swarmers are about 3/8" long including their wings. Their body is a pale yellowish brown and a fontanelle (front gland pore) is indistinct or absent.

The wings have two prominent hardened veins in the front portion. The wing membrane is translucent, almost colorless, with a few barely visible hairs. The front wing is larger than the hind wing.

The head of the Desert subterranean termite soldier is rectangular in shape, the length about twice the width. It also has a fontanelle (front gland pore) on the forehead. The body (pronotum) is flat and almost as wide as the head.

The Desert subterranean termite soldiers have long powerful pointed jaws (mandibles) that are slender, fairly straight but slightly curved inward at the tip. This contrasts with the mandibles of the Western subterranean termite that are thick and curved.

The small size of Desert subterranean termites and their ability to forage under dry conditions allows them to occupy a niche not exploited by other subterranean termite species.

Identification of Timber Damage: Desert subterranean termites prefer to eat the springwood in timbers, generally avoiding the lignin in summerwood. Damaged timber appears honeycombed, with soil in the galleries.

The Desert subterranean termite is less dependent on moisture and decay than other subterranean termites. It will readily attack dry, sound wood. A typical sign of infestation is the presence of “drop tubes” coming from the ceiling rafters and sheetrock/plasterboard and/or holes in the sheetrock plugged with faeces.

Identification of Mud-shelter Tubes: Desert subterranean termites prefer to forage in shaded soil or areas made wet by irrigation.

They will readily construct mud shelter tubes up, over or around solid objects in order to reach a timber food source. These mud-tubes are slender, solidly built and pale yellow to tan in color.

The mud-tubes are more circular in cross section than those of the Western subterranean termite whose mud-tubes are flattened in cross section and dirty light brown in color.

Biology and Habits: Desert subterranean termites most often swarm at night during the rainy season, from July to September, usually after rainfalls. The moist soil provides the nuptial Desert subterranean termite swarmers with the best chance of surviving and developing a new colony. The male and female pair off and enter the soil where they excavate a cavity or cell.

A well-developed mature colony of Desert subterranean termites may contain more than 300,000 termites, including a large number of secondary reproductives (queens) that can readily break off from the primary colony to form separate colonies. Desert subterranean termites commonly have a foraging territory of up to almost an acre.

Desert subterranean termites require only a tiny gap, about 1/32", in concrete flooring or mortar joints in brick walls to gain access to the wall, roofing and other structural timbers in a building.

The Desert subterranean termite can penetrate cracks in concrete and masonry that are too narrow for foragers of other subterranean termite species to enter.

Desert subterranean termites often build their mud-shelter tubes as free standing tubes that "drop down" from rafters, ceilings and subfloor areas under buildings.