Formosan Subterranean Termite: a destructive specie

Published on 16 June 2021
formosan termite

The Formosan Subterranean termite, scientifically known as Coptotermes formosanus, is the most destructive termite specie due to its colony size. The Formosan termites come from Asia and, arrived in the USA in the 1950s. Formosan termite are invasive pests causing hundreds of millions of dollars per year in damage in the United States.

Identification of the Formosan termite

Formosan termites are classified as subterranean termite, meaning that they establish their colony underground, but Formosan termites differ from other subterranean species with their ability to establish a nest (aerial colonies) or secondary nest above ground as long as it is in the dark, hidden and moist – such as within walls, in attics and trees (even the healthy ones). When establishing their colony and living underground, Formosan termites can go as deep as the groundwater table for 1 linear acre. Their carton nest is made of termite excrements, chewed wood, and soil.

As in other termite species, Formosan termites’ specie is categorized into 3 castes:

  • The workers: eat the cellulose in wood and feed the rest of the colony.
  • The soldiers: protect their colony and are orange-brown with an oval-shaped head (tear drop) with large dark mandibles.
  • The reproductives: also known as alates or swarmers, the future kings and queens of new colonies. They are about 5/16-inch-long (14-15mm) and are yellow. They have wings which break off once they found a new area to start a new colony during the swarming season.

Why is the Formosan termite specie dangerous?

While the native subterranean species in the USA gather about 1% to 2% termite soldiers, the Formosan termite specie gathers 10% to 15% termite soldiers. Because of this significant quantity of termite soldiers, the Formosan specie is the most aggressive specie. Formosan termite colonies are often 10 times the size of other Subterranean termite species. Indeed, a colony contains millions of termites, and a mature queen can lay up to 3000 eggs a day. So, the colony grows fast and is very destructive– the infestation can happen sooner than you would think.

Formosan termites are also more resistant thanks to their ability to build a secondary carton nest in the walls of a structure that do not require to return to the soil like most subterranean termites do and this carton nest hold enough moisture for them during dry periods.


To travel above ground, Formosan termites leave mud trails, meaning that you can spot them by looking for mud trails or mud tubes – you can find these on walls or in door jams. Anything that is connected to some wood attracts termites and they can enter any home through the tinniest holes. You can also notice some damages around the windows, but also on PVC pipes because they can chew through non-wooden materials. They eat all the wood present in your home, such as furniture, books, doors, walls, wooden frameworks, etc. A piece of wood infested by termites sounds hollow when you tap on it.

termites leaving mud trails mud tubes
formosan termite wood damage

Formosan termite localization and swarming season

The Formosan termite specie was transported to the United States in the 1950s by human movements with the transportation of any wooden materials. Their presence has widespread ever since to different states via the same way and maybe by hurricane or severe windstorm. This specie is now found in Alabama, Arizona, California, Florida, Georgia, Hawaii, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Texas, and Virginia.

During spring time, alates, or swarmers, leave their nests and fly to a new location to mate and create another colony. The swarming season of the Formosan termite specie happens from April to July, especially during humid evenings.