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Plant Industry - Structural Pest Termite Control

TERMITES AND THEIR CONTROL

Termites are one of the few groups of animals capable of eating and obtaining nourishment from cellulose materials which are readily available in homes and other buildings. Termites have been inhabitants of the earth for millions of years. These insects are able to digest wood because they depend on the protozoa (one-celled animals) in their hindguts to digest the cellulose, a major component in wood. They were originally scavengers of dead wood in the forest, but as civilization developed, their natural habitat decreased and they were forced to seek out wooden buildings for a source of food supply. Termites are now one of the most costly economic pests. It is estimated that between $1-3 billion is spent annually for control measures and to repair the damage done by this insect.

The majority of damage caused by termites in the United States is caused by the eastern subterranean termite (Reticulitermes flavipes). The colonies or nests of this pest are built in the soil from which they obtain moisture. From their nests, they range out to feed. Although they mainly feed on wood, they also attack any material containing cellulose (e.g., paper, books, cardboard, etc.) and can occasionally severely damage living plants by hollowing out the stems. Subterranean termites typically damage the interior of structural beams, flooring, etc., and leave the surface intact. The first signs of an infestation may be swarming of the reproductives or mud tubes on the surface of walls, joists, piers, chimneys, plumbing, and other locations. Other signs of a termite infestation include weak or broken structural members, blistered wood, and soil in cracks. The interior of a damaged beam typically has galleries containing mud. The damage is greatest to the soft spring wood. A homeowner does not discover some infestations until a floor or wall collapses.

There are two additional species of economically important subterranean termites found in Georgia R. virginicus and R. hageni. For the purposes of this information sheet, no distinction will be made between these three species since they all have similar biology and can only be separated by an expert.

There are other types of termites that may attack wooded structures. Drywood termites are able to establish colonies in wood that is not decayed nor in contact with the soil. Drywood termites are a little larger than subterranean termites. The alates or swarming reproductives and soldiers are up to ½ inch long. The swarmers often have a reddish tint. Drywood termites are not considered a serious pest in Georgia.

The Formosan termite (Coptotermes formosanus), a native of China and Taiwan, was found in Charleston, S.C. in 1957 and in Houston, Texas in 1965. Since then, it has become established in Galveston, Texas, New Orleans and Lake Charles, Louisiana, and Broward County, Florida. Efforts have been made to limit the spread of this termite to points of entry. Infestations of this termite have been limited to a few localized infestations. Each of these infestations was linked to infested wood (most frequently railroad ties) brought into Georgia from areas where the Formosan termite has been established.

The Formosan termite is more aggressive than native species of termites and may displace them when foraging areas overlap. Formosan colonies may contain 4-5 million individuals. This termite has the unique ability to construct cartons and live without a ground connection as long as there is a suitable constant water supply.

BIOLOGY AND HABITS OF SUBTERRANEAN TERMITES

Subterranean termites are social insects that live in nests or colonies in the ground. A colony, whether it has only a few individuals or has tens of thousands in it, is composed of three major forms or castes - reproductives, workers, and soldiers. Each individual passes through three stages during their lifetime - egg, nymph, and adult. The adult workers and soldiers are similar in appearance. They are both wingless and grayish white; however, the soldiers have larger heads and longer jaws. The workers make up the most individuals in a colony and are the forms that destroy the wood. The soldiers guard the colony.

Winged reproductives, or alates, are yellow-brown to black in color and are a little less than 1/2 inch (10-12 mm) in length. They have two pairs of wings which are approximately equal in size and longer than the abdomen. The prenuptial flight or "swarm" occurs most frequently in early spring, however, they can occur anytime during the spring, summer or fall. The eastern subterranean termite usually swarms during the day during the months of February through May in Georgia. During each swarming season, alates will embark on a "prenuptial flight" in order to find a mate and establish a new colony. When emergence is within a building, alates are attracted to strong light and gather around windows or doors.

Following the prenuptial flight, males and females (now called the king and queen) pair in tandem with the male following the female. They come back to earth, drop their wings, and commit themselves to their new location. They immediately begin digging a new nest in the ground and lay the first eggs. If they are lucky, they will make it through the first year. Several years must pass before the colony will be large and stable enough to produce alates.

HOW TO RECOGNIZE TERMITES

Termites and ants can be confused. The termite workers, which are white in color and wingless, are often called "white ants". There are, however, several differences which can be readily seen.

HOW TERMITES INVADE BUILDINGS:

Termites can enter a building by several methods:

HOW TO DETECT TERMITES IN BUILDINGS

The appearance of winged or swarming termites is often the first indication of a problem. Although the swarm poses little or no immediate danger to the structure, it gives warning of termites in, or in close vicinity, and the homeowner should make an effort to locate the source from which they are emerging.

Earthen shelter tubes, constructed over surfaces of foundation walls, or sometimes directly connecting the soil and the structure, are another readily visible sign of termite infestation. These tubes are between 1/4" and 1/2" or more wide. If it is in use, the inside is moist and there may be white workers present. Also, if a section is broken, the workers will repair it as soon as possible because it is used as a passageway between the wood and the soil from which they obtain essential moisture. The tubes also protect the termites from the drying effects of direct exposure to air.

Without the external evidence of winged termites or visible shelter tubes, it is more difficult to determine whether or not termites are present in a building. The first place to be checked is the wood which is near or rests on the ground. Weather boarding, wood supports, basement window frames, door casings, sills, etc., can be checked for soundness by being tapped with a hammer and probed with a screwdriver. If hollow wood is found, and it is the result of a termite infestation, the soft portions of the wood will be eaten leaving the hard sections.

PREVENTION OF TERMITES DURING CONSTRUCTION

The best control of the subterranean termite is prevention. Too much emphasis cannot be placed on the fact that the best time to provide protection against termites is during the planning and construction of the building. The following practices should be considered essential in any building operation.

CONTRACTING WITH COMMERCIAL STRUCTURAL PEST CONTROL COMPANIES

The most frequent concept for control for subterranean termites is to prevent or break the contact between the termite colony and wood. Soil treatments are usually not intended to kill termite colonies. If done properly, soil treatment creates an effective barrier against subterranean termites entering and damaging a structure. For the majority of people, termite control is not a do-it-yourself project due to the lack of the necessary equipment needed to do a thorough job.

Another concept for termite control is to feed the termites a toxicant that will perhaps eliminate the colony or at least significantly reduce the populations of the termite colony. The use of baiting systems requires an understanding of the biology of the termites and periodic monitoring of the baiting systems at appropriate intervals. Again, for most people, this is not a do-it-yourself project.

Before signing a contract with any pest control company, get treatment estimates from several different companies. Ask questions about termites, how they will treat your house, cost of treatment, yearly inspection, types of guarantees etc. After you have narrowed your selection to two or three companies, contact the better business bureau for additional information on the companies.