The Western Subterranean Termite is restricted to the western states, ranging from British Columbia south to western Mexico and east to Idaho and Nevada.
Subterranean Termite Recognition
There are three castes of Subterranean Termites, the Swarmer, the Worker and the Soldier. The case you are most likely to see is the Swarmer, which is about 3/8” long including wings, with a dark brown to almost black body and they have two pairs of wings which are the same size. The Worker caste are white to nearly translucent and typically 1/8″ long. The Soldier caste has a dark brown rectangular head with visible mandibles and can be up to 1/4″ long.
Subterranean Termite Damage
Subterranean Termites eat mostly the spring wood and leave the summer wood, giving the damaged wood a layered appearance. Also, soil is typically found in the galleries.
A typical mature colony of 60,000 workers can eat 1/5 ounce of wood each day. At this rate, such a colony could completely consume 2.3 linear feet of a pine 2”x4” board in one year. However, established colonies can have over 1 million workers, potentially damaging an excess of 40 linear feet of 2”x4” boards per year.
Subterranean Termite Biology
Subterranean Termites have three castes: worker, soldier and reproductive. Colony founding proceeds with the swarmers associating in pairs, breaking off their wings and burrowing into the soil. Here they mate and only a few eggs are produced the first year. When the queen is mature she can produce up to 10,000 eggs per year. The queen may live for up to 25 years and workers can live up to 5 years. Several years are required before the colony reaches the typical mature size of 60,000 or more workers and swarmers are not produced until the colony reaches maturity. Swarming takes place in the spring, occurring in the daytime on dry days.
The colonies are located in the ground, usually just above the water table or any rock formations. Mud tubes are built to cross areas of adverse conditions between the colony and the food sources and they can enter structures through cracks less than 1/16” wide. However, if a constant source of moisture is available (such as leaky pipes), colonies (called secondary colonies) can exist above ground and without ground contact.
Subterranean Termite Control
Due to the high survival instinct of the Subterranean Termites, if you find feeding tubes or other activity in or near your home, it is very important that you DO NOT DISTURB them and promptly arrange for an inspection and treatment by a trained and licensed pest control operator.
Effective control of Subterranean Termites involves placing a chemical barrier between the colony and the wood of the structure. In addition, all wood-to-soil contact should be eliminated, and wood debris must be removed and the wood moisture content should be reduced to below 20%. Secondary colonies can be controlled by correcting the moisture problem to dry out the moisture-source area.