Gerald J. Lenhard, Louiana State University

Class: Insecta

Order: Isoptera

Family: Rhinotermitidae

Synonym(s): Formosan termites

Adult Description: Formosan Subterranean termites (Coptotermes formosanus) are considered social insects. Three forms, called castes, are found in colonies - reproductives (winged or wingless), soldiers, and workers (pseudergates). Soldiers and winged reproductives (alates) are the castes used for identification.

Workers: Formosan termite workers are white to off-white in color and are difficult to distinguish from other termite species. Although ants often swarm at the same time of year as do termites, it is easy to distinguish ants from termites by the shape of their bodies, wings, and antennae. They are also referred to as psuedergates

Soldiers: Formosan termite soldiers have tear dropped or egg-shaped heads compared to the more rectangular head of native subterranean termites. Formosan termite soldiers are more aggressive than native subterranean termite soldiers. When disturbed, they will exude a small amount of a white defensive secretion from a gland called the fontanel, located on the front of the head. They can also attach themselves to a finger with their mandibles (mouthparts). Soldiers will make up between 5-10 percent of a colony.

Reproductives: Formosan Alate Winged reproductives (swarmers): Winged Formosan termite reproductives or "swarmers" are yellowish-brown and 12-15 mm (0.5-0.6 inch) in length. They swarm at night in late May and early June and are attracted to lights. They have a dense covering of hair on their transparent wings.

Larva Description: Termite larvae typically hatch within a few weeks. They are approximately the same size as the eggs from which they hatched and are immediately tended to by worker termites. Termite larvae do not directly cause damage to infested homes. However, they comprise a large part of a termite colony and require constant feeding; worker termites ingest wood in order to feed the colony's larvae.

Host Plant: None

History: The Formosan subterranean termite was first described as a species in 1909 from specimens collected on the Asian island of Formosa (currently known as Taiwan). It is now generally accepted that the termite is native to China and it is considered a serious structural pest whenever it occurs. The Formosan subterranean termite has been found in Japan, Sri Lanka, Phillipines, Guam, Hawaii, South Africa and the continental United States. Although officially reported in Hawaii in 1913, newspaper reports indicate that the termite was on the island as early as 1869. The first report of the Formosan termite in the continental U.S. was from a Houston shipyard in 1965. It was reported in Louisiana in 1966 and Charleston, South Carolina in 1967, and has since spread across the southern U.S.

Biology: As with native subterranean termites, Formosan termites initiate new colonies by sending out winged reproductives (alates) from established colonies. Swarms occur from May to June in Florida and Louisiana, and from May to July in South Carolina. Formosan termite swarms occur from dusk to midnight and the alates are attracted to light. After a short flight (usually not more than 20-50 yards) the alates lose their wings, pair off, and seek a small crevices in moist wood to begin the new colony. It takes 3-5 years for a mature colony to develop from a queen, which lays approximately 2,000 eggs/day. Mature colonies can have a population of 10 million foraging workers, soldiers, a primary queen, and several secondary reproductives. The foraging territory of a mature colony can occupy several thousand square feet.

Ecological Threat: The Formosan termite is known to attack over 50 species of living plants as well as structural lumber. This termite is often described as aggressive in both its feeding habits and foraging tendencies. They cannot penetrate concrete, but have been known to attack non-cellulose materials like plastic, asphalt, and thin sheets of soft metal. Although laboratory studies indicate that the individual Formosan termites eat slightly more wood than the native subterranean termites, larger colonies can cause severe structural damage to unprotected homes in 2 years.

The Formosan subterranean termite usually enters structures from colonies maintaining contact with the ground to provide the necessary moisture requirements. However, the Formosan termite, more than the native subterranean species, is able to initiate colonies, which have no ground contact (aerial colonies). It is estimated that 25% of the infestations in southeast Florida have no ground contact. In contrast, native subterranean form aerial colonies only in rare instances (less than 1%). Thus, the voracity, adaptivity to new conditions, as well as the overwhelming number of individuals within a colony enables the Formosan subterranean termite to be an impressively destructive invasive pest species.

US Habitat: Nests:
Formosan termites often form aerial nests made up of chewed wood, soil, saliva and fecal material. These nests can be as large as several cubic feet and found in both the soil and above ground level. They will not be discovered unless the wall coverings are removed. Subterranean nests are typically located away from structures and can be difficult to find.

Distribution

Native Origin: Asia: specifically the Island of Formosa Taiwan from which the termite gets its name.

US States: In the past 15 years the Formosan termite has been identified in Broward and Dade counties in Florida (1980-83). Mobile, Lee, and Baldwin counties in Alabama (1985-87), Memphis, Tennessee (1985), North Carolina (1990), San Diego, California (1991), and Atlanta, Georgia (1993). It is believed that these infestations were transported in infested building or plant materials from areas where the termites were well established.

TEXAS:
The first infestations of Formosan termites in Texas were discovered in 1956 around the Houston Ship Channel in Pasadena, Harris County. Since then, Formosan termites have been detected in 30 Texas counties. There have been reports of Formosan termite infestations in all the major metropolitan areas in Texas. It is believed that Formosan termites were transported to the Houston Ship Channel in wooden shoring timbers from the Far East.

Texas:

Resembles: Formosan subterranean termite workers look similar to those of native subterranean species (Reticulitermes sp). It is almost impossible to identify Formosan termite workers, however the soldiers and alates look very different and are easy to identify.

Management: Homeowners and pest management professionals should watch for isolated infestations. Shoring timbers and recycled railroad ties are often taken from docks and railways and are then used for the construction of terraces or backyard planting beds. This wood is thought to be the primary mechanism for spreading the Formosan termite in Texas. Creosote treatment frequently does not reach the core of these timbers and by itself is not guarantee against Formosan termites. These timbers must be properly fumigated to prevent termites from traveling within them and infesting the soil at a landscaping site.

Text References

Grace JK, Tome CHM, Shelton TG, Oshiro RJ. 1996. Baiting studies and considerations with Coptotermes formosanus (Isoptera: Rhinotermitidae) in Hawaii. Sociobiology 28: 511-520.

Scheffrahn RH, Su N-Y. 1994. Keys to soldier and winged adult termites (Isoptera) of Florida. Florida Entomologist 77: 460-474.

Su N-Y. 2003. Baits as a tool for population control of the Formosan subterranean termite. Sociobiology 41: 177-192.

Suszkiw J. 1998. The Formosan termite: A formidable foe. Agricultural Research 46: 4-9.

Internet Sources:

http://www.invasivespeciesinfo.gov
http://www.ars.usda.gov
http://edis.ifas.ufl.edu
http://www.bugwood.org
http://urbanentomology.tamu.edu/termites/formosan.cfm
http://www.invasive.org

Data Source

Last Updated: 2011-09-26 by Amber Bartelt - Sam Houston State University