It is said... "There are two types of homes in Arizona... Those that are infested with Subterranean Termites and those that will become infested with Subterranean Termites".

Subterranean Termites

The three principal types of termites in Arizona are subterranean (nest in the soil), dampwood (infest dampwood), and drywood termites (infest dry wood)... Arizona residents really do not encounter these types of termites. Subterranean termites are the most destructive and frequently encountered kind of termite found throughout the state. Although they nest in soil, subterranean termites can attack structures by building tubes that connect their nest to wood in structures.

Biology

This termite is known to have major swarms occurring in April, but small flights can occur at any time of the year. Swarming is the primary way the termite naturally spreads after it has been transported to a new area. Three elements are needed for swarming to be effective: 1) Proper food resources (cellulose and wood), 2) moisture, and 3) a physical niche.

As the colony grows, specialized castes are produced for the different tasks required. The first caste produced is the workers. The second caste produced are the soldiers. The third caste to appear are the reproductives. Two types, primary and supplementary, are produced in a Formosan subterranean termite colony. The two types have different functions. Primary reproductives swarm and start new colonies. They are called alates or swarmers. Although thousands of primary reproductives are produced each year, they all leave the nest. Primaries cannot become reproductive if they remain in their colony of origin. In a Formosan colony, the only primaries that reproduce are the original king and queen that started the colony. Supplementary reproductives, on the other hand, can become reproductive only in the colonies in which they were born. They take over reproduction when the primary king or queen dies or becomes separated from the main colony.

Subterranean termites are ground-dwelling social insects living in colonies.  These termites have the ability to adjust the depth of their colony (nest) in soil depending on temperature and moisture requirements. The colony may be 18-20 feet deep in the ground. The ground  serves as a protection against extreme temperatures and provides a moisture reservoir. Termites reach wood or cellulose materials above ground by constructing and traveling through earthen (mud) tubes. The mature colony consists of three castes: a) reproductives (king and queen), b) soldiers, and c) workers. It takes about 4 to 5 years for a colony to reach its maximum size and it may consist of 60,000 to 200,000 workers. 
    

Subterranean termites feed on wood or other items that contain cellulose, such as paper, fiberboard, and some fabrics derived from cotton or plant fibers. Termites have protozoa in their digestive tracts that can convert cellulose into usable food.

Subterranean termites nest in the soil to obtain moisture, but they also nest in wood that is often wet. They easily attack any wood in contact with the ground. If the wood does not contact the soil, they can build mud tunnels or tubes to reach wood several feet above the ground. These tunnels can extend for 50-60 feet to reach wood and often enter a structure through expansion joints in concrete slabs or where utilities enter the house.

Detection of Termites

Termites remain hidden within wood and are often difficult to detect. However, subterranean termites may be detected by the presence of winged reproductives, mud tubes, and wood damage.

Winged Reproductives 

Winged reproductives emerge from colonies in great numbers usually in the spring and during the daylight hours. Usually termites are first noticed by the presence of winged reproductives. Mating occurs during these flights, and males and females form new colonies. Winged termites can be distinguished from flying ants by their thick-waist, straight antennae and wings of equal size.

Winged termites in a house are an indication of probable infestation. Termite wings break off shortly after their flight, and even though the actual swarming is not observed, the presence of discarded wings indicate that a colony is nearby. Because termites are attracted to light, their broken-off wings are often near doors or windows where the termites have been attracted to the light.

Winged termites emerging from the ground out-of-doors near the house does not necessarily mean the house is infested, but it is a good reason to check further. Termites in the wood of homes or other buildings usually come from colonies already established in the soil.

Peak swarming periods for subterranean termites are usually from January through May in Arizona. They may also swarm to a lesser extent during the other months.

Mud Tubes

Subterranean termites build earthen, shelter tubes to protect them from low humidity and predation. These tubes are usually 1/4 to 1 inch wide. Houses should be inspected at least once a year for evidence of tubes. If the house has a crawl space, the inside and outside of foundations should be inspected for tubes. If the house has a concrete slab floor, cracks in concrete floors and places where pipes and utilities go through the slab should be closely examined. Cracks in concrete foundations and open voids in concrete block foundations are also hidden avenues of entry.

Wood Damage

Wood damaged by subterranean termites is often not noticed because the exterior surface usually must be removed to see the damage. However, galleries can be detected by tapping the wood every few inches with the handle of a screwdriver. Damaged wood sounds hollow, and the screwdriver may even break through into the galleries.

Subterranean termite feeding follows the grain of the wood and only the soft springwood is attacked. Unlike drywood termites or other wood-boring insects, subterranean termites do not push wood particles or pellets (fecal material) to the outside, but rather use it in the construction of their tunnels. This debris, along with sand and soil particles, is used as a form of plaster.

Identification
                                                

Termite colonies consist of specialized forms, such as the reproductive queen (top) and king (right), worker (left), and soldier (center). Although they are superficially similar to ants, termites have a closer relationship to the cockroach than to any other living insect.

Subterranean and drywood termites require completely different management methods; therefore, the termites must be correctly identified. Soldiers, winged specimens or wings can be identified at your county extension office. Workers and immatures are virtually impossible to identify. If you decide that the services of an experienced pest control operator are needed, contact at least two or three reputable firms in your area for inspections and estimates for treatment.

Termite Inspections are ESSENTIAL if you wish to protect your investment.  Who is going to look out for your interests and perhaps the most important investment of your life.