Problem:

Subterranean termites

These wood-feeding insects cause more structural damage to buildings than any other insect. Subterranean termites live in colonies as deep as 5 feet in the ground and move up to infest wooden structures through tubes of soil they build over masonry or metal to bridge the gap from soil to wood. Except for the dark, winged swarmers, these termites are white, wingless, and very sensitive to moisture loss. They always remain within the nest, soil tubes, or infested wood, protected from desiccation and insect predators. Within their colony, termites maintain a complicated caste system that includes sterile workers and soldiers, winged reproducers, and an egg-laying queen. Colonies are formed when a pair of winged reproducers leaves the parent colony and excavates a nest in a piece of wood on top of or buried in the ground. As the new colony develops, galleries are formed deep in the soil. Termite colonies develop slowly-3 or 4 years usually pass before the reproductive swarmers develop, and structural damage may not be noticed for several more years. When buildings are erected over established termite colonies, however, serious damage may occur within a year. Termites hollow out the inside of a wooden structure, leaving only an outer shell. Damage is most severe when they infest main supporting wooden beams and girders. One species of subterranean termite, the Formosan termite (Coptotermes formosanus), is not native to the United States but is present in areas of the Southeast and Southwest. This termite is more vigorous and aggressive than native North American species and is more difficult to control.