Termites: The Formosan Termite
Those of you who live in areas of the United States, or the world, where this species of termite –The Formosan Termite – is present will speak of it in terms of dread. You undoubtedly are familiar with this creature, realize the devastation it can wrought, and perhaps even have witnessed the destruction.
Why is termite control so mysterious?
Well, first of all the pests themselves usually are completely hidden from view during their normal activities, and come to light only when an inspection of the hidden areas is performed, or damage is broken into and discovered during remodeling. Sometimes their presence is discovered when hundreds of them suddenly “swarm” inside the home. Since the majority of termite species live in colonies in the ground it now is a mystery to you how to stop them.
Where did the Formosan Termite come from?
The Formosan Termite was originally described as a species in Taiwan, but it is believed that it originated in southern China. Shipping and transport around the world have allowed the Formosan to hitch hike and re-establish itself in many parts of the world. As a feeder on wood and cellulose it commonly gets into materials such as shipping crates, hulls of boats, lumber and other wood materials, furniture, and even has been found in the corks of wine bottles. In this way it found its way to Hawaii in the late 1800s, to South Africa by the 1950s, and in the 1960s was found in Texas, Louisiana, and South Carolina. In 1980 a well-established colony was found in Florida, and it now ranges commonly along the coastal states from North Carolina all the way to Texas and into Tennessee.
In the early 1990s a single isolated colony was found in a housing area near San Diego, in extreme southern California, but so far this appears not to have spread. On several occasions Formosan Termites have been found on ships in San Francisco Bay, but were contained and eradicated there. Many other countries in the world now have the Formosan well established and must deal with it.
Why is the Formosan Termite different from any other termites?
There are several reasons. One, of course, is that the Formosan is living in areas of the world where it does not belong, and like many of the “exotic” pests that find themselves placed in a new, favorable country, they do not have to deal with the natural enemies they had back home. Termites are prey to mammals that eat them, ants that attack and eat them, birds, lizards, and several fungal and bacterial diseases that attack them in the soil. Without their natural controls they live more easily.
A second reason is the size of the colony of Formosan Termites. While our other species of native subterranean termites may have 200,000 workers (in a really big colony) Formosan colonies easily can have several million (!!) workers, all of them foraging for food or doing the other processes of their social colonies 24 hours a day.
Like other subterranean termites the primary colony of Formosans is underground. A single Primary Queen resides there, living many years and laying many hundreds of eggs each day. The workers forage through the soil, looking for wood to feed on, and a single colony could be foraging an area well over one acre in diameter.
How would I know if I have Formosan Termites?
The visible evidence that tells you that termites are present in your home comes in several ways:
- Winged termites flying around inside your home – all termite species have a “caste” in their society called “alates”, which means “winged”. These are the fertile males and females whose role is to leave the colony and start new colonies in new areas. On a periodic basis they will “swarm”, leaving in huge numbers to fly away.
Formosan “alates” are yellowish brown and about ½” long. They swarm after the sun has gone down, at dusk, on warm and humid evenings, usually from April to July. They are attracted to light, so they go to windows and lights. They may also be attracted to your outside porch lights, and this does not necessarily indicate a problem at your home.
- Termites in the wood – should you find wood actually in the process of being damaged, with the termites in it, you can see two kinds of termites here – the workers and the soldiers. The soldiers of the Formosan Termite are very distinctive, with orange, tear-drop shaped heads and jaws that cross each other. There usually are many more soldiers in a Formosan Termite colony – about 1 soldier to every 8 workers, and this may be a clue as well.
- Carton – as Formosans work they create a hard matrix called carton, and they live within it. The carton is the color of the wood they have been eating and looks much like a sponge, although it is very hard and may fill entire wall voids.
- Aerial nests – unlike other kinds of subterranean termites, the Formosan Termite may nest above ground, perhaps even having no connection to the soil should it be living in a building. It can build large nests of carton in trees, with mud tubing running down the tree trunk to the soil, and through underground tunnels the termites then forage for food.
I’ve read they can chew right through solid concrete and steel!
No, this is not quite accurate. Concrete is a barrier to termites, but there are often tiny cracks in cement slabs or foundations, and the diligent searching of the workers allows them to find these openings through which they then can travel. Formosans are known to attack non-wood materials, such as plaster, plastics, asphalt, or even thin sheets of soft metals such as lead or copper. They certainly are not eating these materials, but may attempt to chew through them in their search for wood or other cellulose. In Hawaii they cause destruction of telephone cables as they chew through the outer plastic to get to paper linings inside.
While it is possible for a mating pair of alates to fly onto your home and begin a colony, the conditions would have to be perfect to allow their survival. This means plenty of moisture would have to be available for them in the walls, and this would only be possible if something was not working correctly – leaking pipes, rain gutters not draining correctly, air conditioners leaking, interior pipes sweating, etc. Properly maintaining your home will go a long way in discouraging termites from getting settled in.
Where flat-topped roofs are common, as they are on many commercial buildings and high-rises, rainwater can pool and sit, providing ideal places for the Formosan to get a foot-hold. In some areas of southern Florida it may be up to 25% of the infestations that begin as aerial colonies.
Usually Formosans, and other kinds of subterranean termites, find their way into your home from below. Since colonies normally are in the soil it is from these sources that workers forage for food. They may enter through expansion joints or cracks in the slab on which your house sits, cracks in the foundation, holes in the slab through which pipes, wires, or other conduits run, or any place where wood is directly in contact with the soil. They also can quickly construct mud tubes on the outside of wood or concrete, and build this little enclosed highway up to the wood, where they then can enter and be hidden once more.
What can I do to prevent the Formosan Termite from attacking my home?
Good building practices and maintenance are vital, even as they are with preventing other kinds of pests from getting into a structure. Wherever wood must touch the soil the use of “pressure-treated” wood is necessary. This also prevents wood destroying fungi from attacking the wood, but the chemicals used in pressure-treating also are toxic to insects. This is not an absolute barrier to the Formosan Termite, for as we mentioned earlier, it is capable of building mud tubes on top of the wood, bypassing any chemicals.
If your house is built with an open crawl-space below you should have this area inspected on a regular basis, and the person most qualified to do such an inspection is a Licensed Pest Management Operator who is trained and experienced in this area. Any kind of cellulose debris laying around in the crawl-space must be removed – boards, papers, boxes, etc. – to remove potential food sources that might encourage termites to work in that area.
Taking a good, critical look at the rain gutters and downspouts, plumbing connections and pipes, shower stalls and tiles, bathtub seals, toilet seals, and anyplace else in your home where water runs is a wonderful idea. Regardless of whether or not these may attract Formosan Termites the presence of “excessive moisture conditions” encourages the growth of fungus that can destroy the wood, and also serves to attract a host of other kinds of insects, from carpenter ants to springtails.
Treatment of the soil, by a Licensed Pest Control Company, is also an excellent preventive measure, as is the use of termite bait, and we will discuss these more in the next section.
Please! I need some good news…
Well, there isn’t any outstanding news, but there are some interesting new tools available that hold promise for holding back the tides of termites a bit. For many years the most effective termite control chemical on the market was called Chlordane. Due to concerns that may or may not even have been valid this product was removed from use in the United States around 1985. It was excellent in preventing termites because it lasted for a very long time, providing protection for perhaps 30 years after a single application to the soil under the house.
Since that time the termiticides (termite control chemicals) appear to be less effective, primarily because they degrade and disappear from the soil so much more quickly. Even when fairly fresh in the soil there may be issues of repellency that allow the termites to avoid the treated area and move around it. A chemical treatment of the soil does NOT kill the colony of termites living below it, but instead places a “barrier” on the soil under your house that termites, hopefully, cannot penetrate without being killed.
Now, however, the two newest chemicals on the market may offer much more effectiveness. One of them is talking all around “colony elimination” without actually saying it, but much of the evidence may indicate that that is what is being achieved. Talk with your pest control company about the use of Premise and Termidor. New discoveries in the chemical industry are finding highly effective materials that are of extremely low risk to warm-blooded animals. Premise, for example, uses the same material that is in some of the veterinarian-prescribed flea drops for cats and dogs.
Termite baiting is the other good news, and this is discussed much more thoroughly in a separate article. There are several trade names available to the professional pest control industry, and they seem to work fairly well. The good news is that Formosan Termites, being the voracious feeders that they are, seem to really enjoy feeding in the bait stations – once they find it, and this remains the drawback with termite baiting. If everything goes well the foraging termites will take a continuous stream of toxic food back to their colony and completely eliminate all the workers and the Queen. In Hawaii extensive use of termite baits has shown some excellent results, so consider asking your pest control company about this as well.
Baiting for termite control will work for any of the “subterranean” termites, but many of our pest species still seem to be somewhat picky about it, and their feeding activity on the baits and monitoring materials in commercial bait stations is somewhat erratic.