Texas Cooperative Extension Harris County

Drywood Termites

Phillip J. Hamman and Roger E. Gold - Extension Urban Entomologist and Professor, Entomology Department, The Texas A&M University System

In nature, termites are scavengers which break down trees and other wood that accumulates in forests. The products of this breakdown process are returned to the soil as humus. When termites invade human structures, problems begin. Drywood and subterranean termites are the most destructive insect pests of wood, causing more than $1.7 billion in damages each year in the U.S. Their presence in structures is seldom noticed until damage is discovered. Homeowners can take certain preventive measures, but chemical control requires the services of qualified pest control operators.
Drywood termite distribution in Texas

Distribution

Drywood termites are found in the southern tier of states, from North Carolina through the Gulf Coast and into the coastal areas of California. In Texas, drywood species have been found from Beaumont to the Rio Grande Valley and inland to the San Antonio-Austin area. Most of the damaging populations seems to be confined to counties along the Gulf Coast, primarily in the Rio Grande Valley northward through Corpus Christi and into the Houston-Galveston-Beaumont areas. The exact range of drywood termite populations has not been fully determined, but is the subject of current investigations by scientists in the entomology department of Texas A&M University.

Description

Drywood termites are social insects that live in nests or colonies in sound, dry wood. Each colony consists of offspring from an originating pair. There are different forms or castes in colonies - reproductives, workers (nymphs) and soldiers. There are three growth stages - eggs, nymphs and adults. Drywood termites are generally larger than most of the commonly seen subterranean species.
Drywood termite soldier & nymph

The reproductives are winged or wingless males and females which produce offspring. The primary reproductives, also called swarmers or alates, vary in body color from dark brown to light yellowish tan. Their wings may be almost clear to smoky gray, and have few distinct veins in them. Swarmer drywood termites are about 7/16 inch long, including wings. Secondary reproductives are found in the colony only after one or both members of the primary pair have died. Drywood termite swarmer

Ants and termites often swarm at the same time of the year. It is important to distinguish swarming ants from termites, since control measures for these two insects are quite different. Winged termites can be distinguished from winged ants on the basis of the characteristics show in the illustration.

In most drywood species there is no true worker caste, as this function is taken over by nymphs. These nymphs are wingless, white to grayish in color, 1/4 to 3/8 inch long and make up the largest number of individuals within a colony. They gather food, enlarge the nest and feed and care for the queen, immature forms and others in the colony.

Soldiers resemble workers in color and general appearance. However, they have large, well-developed brownish to yellowish-brown heads with strongly developed mandibles or jaws. Soldiers defend the colony against invaders, primarily ants. Members of this caste are about 5/16 inch long. In one or two species that have been found infesting furniture brought into Texas from southern Florida and Central or South America, the soldiers have broad, high, blunt heads that are used to plug up holes in the nest to prevent the invasion of predators.

Resources

For more information contact:

Paul Nester
Extension Agent - IPM
Fire Ant Project
Harris County
Phone: (281) 855-5600

the Texas AgriLife Extension Service - Harris County

the Texas AgriLife Extension Service-Harris County