Termites are social insects with a caste system that includes reproductives

Termites are social insects with a caste system that includes reproductives, workers and soldiers. Each caste has a unique role in the colony. The soldiers defend the colony against invaders (typically ants) and the reproductives yield new colonies. What makes termites a concern for humans is the worker caste, which bore through wood by digesting cellulose material from structural timbers.

A colony begins when the primary reproductives, also called the king and queen, mate and lay eggs. The eggs hatch into nymphs. The queen determines which caste the nymph will belong to based on the needs of the colony. She then secretes chemicals that transform the nymph into a soldier, worker or reproductive. The termite's type/caste is determined by the secreted chemical.

While there are thousands of different termite species, there are three major species that are of economic significance in the United States…

Termite Biology

Formosan termites

Subterranean Termite Treatment - Chemical Treatment

Subterranean Termite Treatment - Baiting Systems

Pacific Dampwood Termite

Subterranean termites

Subterranean termites are the most common termite in the United States. A mature colony has from 60K to 300K workers. The average colony can consume a one foot length of 2x4 in 118 days. Subterranean termites can enter a home through a crack or void as small as 1/32" in the slab or wall, any lumber in contact with the soil, an earth filled stoop, expansion joints, behind brick veneer, and through rigid foam insulation in contact with the soil.

Subterranean termites have three primary needs: food, which to the Subterranean termite is anything made of cellulose (i.e. wood, cardboard, books); a constant source of moisture, and shelter which is provided to the soil.

Subterranean termite workers are creamy white in appearance and the most plentiful caste in the colony. They forage for food to feed themselves and the rest of the colony. They create tunnels from mud (commonly called shelter tubes) to move above ground.

Subterranean termite reproductives, commonly called swarmers, are the winged members of the colony most commonly seen in the spring when they mate. The entire purpose of the swarmer is to create a new colony. Termite swarmers are often confused with a flying ant. Some common distinctions between the two are: ants have different size wings and few veins whereas a termite swarmer's wings are identical with numerous veins. Ant antennae are elbowed, while termite swarmer antennae are straight. The midsection of the ant is pinched whereas the termite midsection is not.

Subterranean termite soldiers protect the colony against attack. They use their large heads to block holes in the colonies shelter tube and their strong mandibles to crush their enemies.

Formosan termites Back to top of page.

Formosan termites are sometimes called "super termites" due to their ability to cause significant damage in short periods of time. In fact, they are the most destructive wood destroying insect due to their large size and aggressive breeding habits. In fact, a Formosan termite colony can consist of 350 thousand to 2 million workers. Formosan termites are most commonly found in humid coastal and subtropical regions (i.e. Hawaii, South Carolina, Georgia, Florida and Louisiana).

Subterranean Termite Treatment - Chemical Treatment

A chemical treatment is the most common treatment type available for Subterranean termites.

The goal of a Subterranean termite chemical treatment is to establish a continuous termiticide barrier between the termite colony (usually in the soil) and wood in a building. This is done by placing termiticide in the soil on both sides of all foundation elements to provide a barrier preventing termites from entering the structure. Technicians trench the soil and inject termiticide beneath it at 16-inch intervals. They also drill into hollow masonry block foundations and inject termiticide into the block voids. This creates a protective barrier around the property, which is generally good for five years.

Subterranean Termite Treatment - Baiting Systems Back to top of page.

In-Ground Baiting Systems are fast becoming a popular method of treatment for subterranean termites. A subterranean termite baiting system involves placement of cellulose (wood material) bait stations at strategic locations around the perimeter of the home. Worker termites - who constantly forage for wood to feed their colony - locate the cellulose bait stations and leave special scent trails to summon their mates to the food source. The cellulose material in the bait station is than replaced with a chemical inhibitor which retards the molting process in termites, preventing them from growing. The carrier termites then bring the chemical back to the colony and - if everything goes well - spread the inhibitor throughout the remainder of the colony. As a result of the growth inhibitor, the carrier and the rest of the colony will die.

Dampwood Termites

They don't require contact with the soil in order to obtain moisture, but wood with a high degree of moisture is needed. They are usually associated with wood decay. Because of their high moisture requirements, they most often are found in cool, humid areas along the coast.
Pacific dampwood termites (at times called a "rotten wood termite") is a major pest at low altitudes along the coastal areas of California, Washington and Oregon.

Winged reproductives are dark brown with brown wings. Soldiers have a flattened brown or yellowish brown head with elongated black or dark brown mandibles. Nymphs are cream-colored with a characteristic spotted abdominal pattern caused by food in their intestines.

Dampwood termites nest in wood buried in the ground.

In nature, they are commonly found in tree stumps and fallen tree branches. In your home the most likely areas to find them would be an older wood deck, leaky roof eaves, leaky showers or tubs, or substructures with inadequate ventilation or plumbing leaks.

The Dampwood termite is much larger than the drywood and subterranean, measuring in at 3/8 to 3/4 of an inch. They can swarm periodically throughout the year and it is common to see the swarming reproductives caught in spider webs next to exterior lights since they are instinctively attracted to light.

The work of the colony is done by the immature soldiers or reproductives, there is no worker caste.
Swarms are small.

They produce a fecal pellet similar to the drywood termite's, but it is slightly larger and has a more irregular shape. Damage in wood can be identified by a velvety appearance in the galleries.

They produce distinctive fecal pellets that are rounded at both ends, elongate, but lacking clear longitudinal ridges common to drywood termite pellets; flattened sides are noticeable.

Control of Dampwood Termites:

Chemical treatment may be not necessary for the control of dampwood termites. Since the dampwood termite requires wood with a high moisture content, correction of the moisture source is necessary. This normally means replacing the existing infested and saturated wood in conjunction with elimination of the moisture source.

Common correction methods:

Increase the ventilation in the affected area, reducing the moisture and repair leaky showers and plumbing.

Make sure you have proper drainage.

Construction needs to be designed to avoid contact of wood and soil.

If the damp wood is not accessible to be removed, treatment of the soil with an effective insecticide or termite baiting systems would be necessary. Back to top of page.