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.
- 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 2×4 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 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).
- Dry-wood termites feed and nest in wood which has a relatively low moisture content. Unlike Subterranean termites, they do not require any contact with the soil. These termites are usually found in the humid coastal and subtropical regions (i.e. California, Hawaii, Florida, Arizona, South and North Carolina, New Mexico, Texas, Alabama, Mississippi, Louisiana and Puerto Rico). They usually infest attic spaces or exterior wood members exposed to them when they swarm in early spring or summer. Typical evidence of dry-wood termites include damage, wings, pellets (fecal matter), and entrance/exit holes.