The Formosan subterranean termite has been transported worldwide from its native range in southern China to Formosa (Taiwan, where it gets its name) and Japan. Within the last 100 years it has become established in South Africa, Hawaii and the continental United States. The first record of Formosan termites in the continental United States was in 1957 from Charleston, South Carolina. In 1965 it was found in a shipyard in Houston, Texas and within a few years colonies were discovered in Galveston, Texas, and New Orleans, Louisiana. It is believed that the Formosan subterranean termite was transported to port cities on the Gulf of Mexico and southeast Atlantic coast by ships returning from the Pacific Theater at the end of WWII. Currently, Formosan termites are found in Alabama, Georgia, Florida, Hawaii, Louisiana, Mississippi, North and South Carolina, Tennessee, and Texas, while an isolated population was found near San Diego, CA in 1992.

     In Florida, they have been found in Crystal River, Dania, Ft. Lauderdale, Hallandale, Hollywood, Jensen Beach, Jupiter, Miami, Orlando, Palm Beach Gardens, Tampa, Tallahassee, Pensacola, and several other western panhandle communities. Within the last two years, they have been discovered in Ocala (Marion Co.), Jacksonville, Trinity (Pasco Co.), Marco Island (Collier Co.), Bonita Springs (Lee Co.) Debary (Volusia Co.), Cape Coral (Lee County), and Interlacheon (Putnam Co.).

     The Formosan subterranean termite has the potential to spread throughout the whole state. Young colonies living in potted plants, landscape timbers, or infested trees can easily be transported. A good example is given in Louisiana and Georgia where their spread was aided by homeowners who accidently brought termites to their homes by buying infested railroad ties at home and garden shops. Alates (winged reproductives) also can swarm from infested boats into new locations as the boats travel from place to place.

 

                                                                                        

Figure 1. Distribution of the Formosan subterranean termite in the U.S.

 

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The Life Of A Formosan Subterranean Termite

     In Florida, Formosan termite swarms usually occur from April through July on calm, warm, and humid evenings. Swarms are quite large with up to tens of thousands of alates. The swarmers are attracted to lights and are often found around windows, light fixtures, windowsills, and spider webs in lighted areas. After swarming and landing on the ground, the alates break off their wings and search for a mate. Once a mate is found, the male and female search for a crevice in damp ground or wood, hollow out a small chamber, and crawl inside. The pair, now known as the king and queen, mate and within a few days the queen starts laying eggs. The young, known as larvae, hatch from the eggs and are fed by the king and queen.

     A mature colony contains distinct groups called castes. These castes look different from one another and each has a special duty within the colony. The king and queen are the primary reproductives and are responsible for reproduction. If the queen or king dies or the colony becomes large, secondary reproductives may form and begin reproduction. Soldiers defend the colony against predators and other natural enemies. Workers take care of and feed the larvae, reproductives and soldiers, tend the eggs, build and maintain the nest, and search for food. Alate nymphs become alates when they are fully grown.

 

     Formosan subterranean termite colonies are much larger than those of native subterranean termite species. Some have been estimated to have over 8 million individuals compared with about 1 million termites in large native subterranean termite colonies.

     Like many other termites, the Formosan termite feeds on wood and other materials that contain cellulose which is the main structural component of plants. Bacteria and other single-celled organisms live in the termite digestive system and digest cellulose providing nutrition and energy for these termites.

 

Do Formosan Subterranean Termites Eat Anything Else Besides Wood?

     Although they feed mostly on wood, they will eat other cellulose-containing materials such as cardboard and paper. However, they are known to chew through foam insulation boards, thin lead and copper sheeting, plaster, asphalt, and some plastics.

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Is It True They Eat Concrete?

     Contrary to popular myth, FORMOSAN SUBTERRANEAN TERMITES DO NOT EAT CONCRETE nor can the soldier's defensive fluid dissolve holes in concrete. These rumors continue because Formosan subterranean termites are always digging through the soil. Because of this continuous activity, they are likely to find cracks and crevices in concrete or mortar and gain entry to a structure. This can fool someone into thinking that Formosan subterranean termites can eat through solid concrete.

 

Where Do They Live?

     Subterranean termite species, such as the Formosan termite, generally live underground. They tunnel through the soil in search of food. Unlike native subterranean termites, Formosan termites build large nests. These are made of carton, a hard material the workers make from soil, chewed wood or plant matter, and their own saliva and feces. Carton nests are quite impressive - a large, rock-like mass constructed by hundreds of thousands or millions of termites.

     Although nesting mostly below ground, some Formosan termite colonies will build above-ground nests that are not connected to the soil. Nests can be made in structures where the temperature does not get too hot or cold and there is plenty of moisture. Sources of moisture include:

 

• plumbing, water heater, and roof leaks

   

• condensation from air conditioning units

   

• poor drainage from gutters and flat roofs

   

• seepage and rainfall on boats and ships

   

• porches, balconies, rooftops, etc. with plants or landscaping that are frequently watered

   

What Do Formosan Subterranean Termites Look Like?

     Formosan subterranean termite workers look similar to those of native subterranean species. It is almost impossible to positively identify Formosan termites with just the workers but the soldiers and alates look very different and are easy to identify.

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Soldier

     Soldiers have orange-brown, oval-shaped heads that are quite different from the more rectangular, straight-sided head of native subterranean termite soldiers. There is a small pore, called the fontanelle, on the front of the head. The soldiers produce droplets of a white, glue-like fluid from this pore when they are attacked. This fluid gums up and disables attackers. Soldiers have black, sickle-shaped mandibles (jaws) that can be crossed to form an X. The bodies are yellowish-white and are about 1/5 to 1/4 inches long. Formosan subterranean termite soldiers are very aggressive. They will even attack fingers or tools if provoked, although their bite and fluid is harmless to humans.

 

 

Alate ("Swarmer")

     Swarmers are yellowish-brown with golden brown heads, a pair of black eyes and 2 pairs of wings of equal length. They are about 1/2 to 3/5 inch long from head to wingtip. The wings are clear with two heavily thickened veins on the leading edge  and are covered with small hairs. These hairs are clearly visible under magnification.

 

 

 

How Can I Get Them Identified?

     If you are not sure if the termites you have are Formosan, you can send or bring soldiers and alates to your County Extension office for identification. Here are some tips for sending or bringing your samples:

 

• Preserve the termites in rubbing alcohol and keep them in a small, non-breakable container with a tight-fitting, leak-proof cap or lid.

   

• Termites mailed in envelopes or sandwich bags dry out, get crushed, and break apart if they are not first put into a sturdy container. This often makes identification difficult.

   

• Do not stick termites on tape or tape them to paper. This makes identification difficult.

   

• Be sure to include the wings if you have alates.

   

     Remember, the better the condition your samples are in, the easier it will be to identify them.

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          How Do I Know If My House Is Infested?

     Large carton nests in trees, attics, wall voids, etc., are obvious signs of an infestation. Sometimes the damage caused by Formosan subterranean termites is not so obvious. Soft spots, damp or moist patches, bulges, and blistered paint or wallpaper in walls, doors, floors, and other areas may indicate termite activity underneath. Probing these areas with a screwdriver may reveal damaged wood, soil, carton, and live termites. Formosan subterranean termite infestations are recognized by the presence of lots of soldiers.

     Subterranean termites crawling above ground build mud shelter tubes because they do not like being exposed in the open to light and air. The tubes keep the termites from drying out and shield them from predators, such as ants, and natural enemies. Shelter tubes are often found on walls coming up from the ground or floor. They may also be found sticking out or dropping down to the ground in crawl spaces, under porches or stairways, etc. Tubes and carton may be in places where they are difficult to see such as stucco or plaster cracks, tree holes, tree crotches, etc. You can break the tubes open to check for termites.

     Remember that Formosan subterranean termites swarm during the evening from April through July. Keep in mind that swarmers outside around your home could be emerging and flying in from somewhere else. Check carefully around the premises to see if they are coming from your property.

 

 

What Should I Do If I Have Formosan Subterranean Termites?

     The best thing to do is to have the infestation professionally treated. There are two types of control available: soil termiticides and baits. The treatment used depends largely on the type and size of the infestation, and which one the homeowner is most comfortable with.

 

Soil Termiticides

Pre-treatment

     Treating soil with a liquid termiticide creates a chemical barrier beneath the structure.  Depending on the chemical, the termites will either avoid tunneling through treated soil or die soon after they come in contact with it. Soil termiticides have been the standard preventive treatment for subterranean termites up until the mid-1990s. Termiticides are applied before the foundation slab of a structure is poured. Under ideal conditions, protection should last from 5 to 7 years; but under less than ideal conditions or because of improper application it can be much less. The slightest break in the protective barrier is all that is needed for termites to reach a structure. They can tunnel through areas in the soil where no termiticide is present. Expansion joints, cracks, and utility and plumbing lines are common termite entry points through a concrete slab. Termiticide breakdown, soil erosion, improper application, and careless construction practices (such as leaving wooden grade stakes in the slab or disturbing treated soil) are several ways that the chemical barrier can be broken.

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Post-construction treatment

     When infestations occur after a structure has been built, termiticides are applied by one of three methods: rodding, drilling, or trenching. In the first, termiticide is injected directly into the soil at specific intervals around the perimeter of the house and beneath the slab with a rodder, an injection tool with a long, hollow, metal rod with an open tip. Drilling involves making holes through concrete slabs, walkways, patios, walls, and floors in order to treat the soil beneath the slab or inside wall voids. Trenching involves digging a shallow trench (about 6 X 6 inches) around the base of the home, applying termiticide to the trench and the backfill and then refilling the trench.

 

 

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