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 or inside home, they are often found in wood floor, wood flames or wood furniture closed to restroom, bathroom, kitchen or window.
Controlling Subterranean Termites
Subterranean and dampwood termites in structures cannot be adequately controlled by fumigation, heat treatment, freezing, or termite electrocution devices because the reproductives and nymphs are concentrated in nests near or below ground level in structures out of reach of these control methods. The primary methods of controlling these termites are the application of termiticides or baiting programs.
Use of termiticides or baits should be supplemented with the destruction of their access points or nests. To facilitate control of subterranean termites, destroy their shelter tubes whenever possible to interrupt access to wooden substructures and to open colonies to attack from natural enemies such as ants.
Dampwood termites only infest wood with high moisture content. Dampwood termites nest in wood buried in the ground, although contact with the ground is not necessary when infested wood is high in moisture. Because of their high moisture requirements, dampwood termites most often are found in cool, humid areas like flowerbeds and are typical pests of beach houses. Infestations in structures usually occur where wood is wetted by moisture leaks. Structures, utility poles, pilings, and lumber exposed to high moist soil and humidity are subject to attack.
Dampwood termites are noticeably larger than subterranean termites. Winged reproductives typically swarm between July and October, but it is not unusual to see them at other times of the year. Dampwood termite winged reproductives (sometimes called swarmers) are attracted to lights. Dampwood termites produce distinctive fecal pellets that are rounded at both ends, elongate, and lack the clear longitudinal ridges common to drywood termite pellets.
For dampwood termites, if infestations are small, destroy accessible nests by removing infested wood. Removing excess moisture from wood will also destroy dampwood termite nests.
Drywood termites are so-named because they live entirely in dry, sound wood. They are well adapted to withstand environmental extremes in both moisture and temperature. Drywood termites colonies are small in comparison to subterranean termties, containing perhaps a few thousands individuals. Drywood termites infest dry, undecayed wood, including structural lumber as well as dead limbs of native trees and shade and orchard trees, utility poles, posts, and lumber in storage. From these areas, winged reproductives seasonally migrate to nearby buildings and other structures usually on sunny days during fall months.
Drywood termites have a low moisture requirement and can tolerate dry conditions for prolonged periods. They remain entirely above ground and do not connect their nests to the soil. Piles of their fecal pellets, which are distinctive in appearance, may be a clue to their presence. The fecal pellets are elongate (about 3/100 inch long) with rounded ends and have six flattened or roundly depressed surfaces separated by six longitudinal ridges.