Formosan subterranean termites


Formosan subterranean termites are a formidable foe for any homeowner. Large colony size and ability to forage over vast distances allows them to cause significant damage to wooden structures in a relatively short amount of time.

As their name suggests, Formosan subterranean termites are an invasive species which came from Taiwan (formerly known as Formosa). In the United States, they are established throughout the southeast and can be found in Alabama, Tennessee, Mississippi, Texas, Georgia, Louisiana, Florida, and the Carolinas. Even though they are “subterranean” termites, they are able to establish nests in areas that are not in contact with the soil. These aerial colonies still require high humidity, which might be from a roof leak or condensation on equipment. They form characteristic carton nests from macerated wood, soil, and their own waste. These rock-hard carton nests are usually found in wall spaces and other voids.

Like most termites, Formosan termites have a caste system which divides tasks among the colony members. These include the workers, soldiers, and reproductives. Identifying termites generally requires examination of a soldier or reproductive; workers look very similar across subterranean termite species.

The workers are plump, white, and blind. They search for food and share it with the colony. A mature colony, one that is three to five years old, can have millions of workers. Formosan termites are considered more aggressive in terms of how quickly they can eat and damage wood compared to eastern subterranean termites. This is not because Formosan termites consume more on an individual termite level but simply because of how large their colonies can get - more termites equals more mouths to feed. The workers forage far and wide, almost the entire length of a football field, making them exceptionally problematic for home and business owners.

The soldiers have orange, oval heads and curved mandibles for defending the colony from predators. They aggressively bite at anything that moves, but their small size makes them harmless to humans. Additionally, they can secrete a white sticky fluid from an opening in their head which is noxious to ants. Soldiers represent around 10-15% of a colony’s population. Compare that to eastern subterranean termite colonies which only contain around 1-2% soldiers. If high numbers of soldiers are seen, then chances are you’re dealing with Formosan termites.

The reproductives, or swarmers, are yellowish brown with four equal-sized wings. They go forth to find mates and begin their own colonies somewhere else. After pairing and mating, the termite couple shed their wings, find a moist area near wood, and become king and queen of a new colony. While there are supplementary reproductives, the queen is the original egg-layer with the most reproductive capability for a single termite.

University of Florida, Featured Creature. Website: Accessed February 2018.