The western subterranean termite, is the most destructive termite (section “1″ category pest / Structural Pest Control) found in California. Reproductive winged forms of subterranean termites are dark brown to brownish black, with brownish gray wings.
Subterranean Termites are smaller than Drywood termites, approximately one-fourth inch long. They create colonies in the soil and require moisture to survive. Unlike Drywood Termites, they do require a direct connection to soil. They build tubes up the side of concrete foundations or straight out of the ground, making highway tunnels for traveling to their food source and back
Subterranean termite is the most destructive species of subterranean termites. Another destructive species in this group, the Formosan subterranean termite, Coptotermes formosanus, is now in California but restricted to a small area near San Diego and Los Angeles. Unlike the western subterranean termite, Formosan subterranean termites swarm at dusk and are attracted to lights.
Subterranean termites require moist environments. To satisfy this need, they usually nest in or near the soil and maintain some connection with the soil through tunnels in wood or through shelter tubes they construct. These shelter tubes are made of soil with bits of wood or even plasterboard (drywall). Much of the damage they cause occurs in foundation and structural support wood. Because of the moisture requirements of subterranean termites, they are often found in wood that has wood rot.