Termite Subterranean Termites

Color: The worker termites are creamy brown.

Size: Approximately 6mm (1/4 inch) in length.

Subterranean termites need contact with the soil to survive and live underground. They can build tunnels through cracks in concrete

It is not known exactly how subterranean termites locate sources of food. It is thought that the termites forage by digging a network of tunnels and come in contact with food sources in the process. The foraging range of a single termite colony is difficult to predict. Some larger colonies may forage over areas the size of a football field. However, depending on the season or weather, they may not forage over their entire range at all times. Also, several smaller colonies may cover a greater foraging distance than one large colony.

Foraging termites produce a variety of chemicals called pheromones that influence their behavior. These pheromones are basically odors that send messages to other termites in the colony. While tunneling underground, the foraging termites lay down a trail of pheromone which they secrete from glands on their abdomen. When a food source is located, the odor trail is intensified to recruit other termites to the feeding site. However, the intensity of the recruitment effort (odor trail) is influenced by soil temperature, moisture and compaction as well as the size and quality of the food source.

Subterranean termites also forage above ground for sources of cellulosic food like wood in homes and other structures. In order to protect themselves from predation by ants and maintain their connection to the soil while searching for food above ground, termites build long tubes out of mud and fecal material. These mud tubes are called exploratory tubes. Termite exploratory tubes are very easy to see and are one of the best ways to identify a potential termite infestation. Once a source of wood has been located, the termites establish more permanent utility or working tubes. The utility tubes are highways running from the underground termite galleries directly to the food source. Utility tubes can cover long distances over the foundation of a building or along exterior walls to reach the wood inside. Sometimes subterranean termites build another tube that runs from the structural wood back down to the ground. These tubes are called drop or suspended tubes. Drop tubes are often lighter in color than the utility tubes because they contain more of the wood fiber taken from the structure. Subterranean termites construct a fourth type of mud tube in addition to those that facilitate foraging. These are called swarming tubes. Swarming tubes are built seasonally extending only 4-8 inches above ground. These tubes provide the exit port for winged swarmers leaving the colony.

Subterranean termites live underground and build tunnels, referred to as mud tubes, to reach food sources. Like other termite species, they feed on products containing cellulose (wood).

Subterranean termites are by far the most destructive species. They can collapse a building entirely, meaning possible financial ruin for a homeowner. The hard, saw-toothed jaws of termites work like shears and are able to bite off extremely small fragments of wood, one piece at a time.

The most effective and economical time to implement termite prevention techniques is during the planning and construction process. Whether pre or post construction, limiting favorable food (wood), moisture and shelter conditions to termites can prevent or help eliminate infestations.

• Exterior wood should be at least 6 inches (15 cm) above ground level, and may require regarding or pulling soil or mulch back from the foundation to eliminate wood-to-ground contact.
• Timbers in crawlspaces should be at least 18 inches (46 cm) from the ground.
• Wood in door frames, stair carriages, wood posts etc., should be cut off at the bottom and be supported by a concrete base. If wood-to-soil contact is un avoidable, wood can be treated with a preservative.
• Wood, cardboard, paper or the other cellulose materials in the soil can attract termites to structure. These materials should not be buried in fills during the construction process.
• Do not use mulch and wood chips around foundation of house. Pea gravel or crushed stone may serve as a substitute for mulch or wood chips.
• Fire wood, landscape timbers, compost piles and other cellulose material should not be stacked close to structure.
• Dense vegetation should not be allowed to grow against the siding and foundation of a building.
• Shrubs, vines and trellises make inspection difficult and can trap moisture, increasing conditions favorable for wood decay and termites.
• High moisture conditions around a structure can contribute to a termite infestation. In addition to reducing vegetation in contact with building, soil around structure should be sloped so that surface water drains away from the structure.
• Proper installation and maintenance of gutters, downspouts, and splash blocks and proper positioning of lawn sprinklers or irrigation systems to avoid pooling water will reduce soil saturation.
• High humidity in crawl spaces can also lead to problems. Plumbing or appliances leaks can lead to damp wood and soil conditions in this area, and areas of crawlspaces beneath potential trouble spot should be inspected and any leaks or problem repaired.
• In some climate or areas, soil conditions themselves may contribute to crawlspace humidity. Polyethylene sheeting can be placed over soil in a crawl space to reduce evaporation from the soil and condensation on structural timbers.
• Adequate ventilation can further reduce moisture problems. A vent area of 1 square foot (0.1 meter square) per 150 square feet (14 meter square) of crawl space area is required for most building codes.
• Plumbing leak can also lead to favorable termite conditions inside structure and may allow a colony to survive above ground with no soil contact.
• Roof leaks or inadequate drainage can be also cause this problem. Water leaking into wood areas below the roof or standing water on the roof surface potentially lead to wood decay or other moisture problems that can be conducive to termite infestation. Special attention should be given to flat or low-pitched roofs where drainage problem may be more frequent.
• Attached planter boxes also bring soil in close proximity to structural timbers and should be separated from the foundation by at least 3 inches (8 cm).
• Use of termite resistant woods may be another non chemical alternative for subterranean termite prevention. California red wood, red cypress and red and yellow cedar have all been shown to have some level of resistance.