Termites, sometimes known as white ants, are a group of eusocial insects usually classified at the taxonomic rank of order, Isoptera. Termites feed on wood and other dead plant material, and several species are economically important as pests that can cause serious structural damage to buildings. Termites are also significant in subtropical and tropical regions, where they help recycle wood and other plant matter. Around 2,750 species have been described so far.

Appearance and Morphology

Termites only superficially resemble ants; their "white ant" name is probably due to their similar size and social habits.

Termites have biting mouthparts and their soft bodies are small, rarely over 10 mm in length. They typically inhabit dark nests and tunnels, only venturing out when the winged alates emerge to leave their parent colony, when constructing shelter or, in the case of grass-eaters, when harvesting grass stems. The bodies of flying individuals are dark, while termites which remain in the nest are whitish with only their heads being lightly pigmented. The deciduous wings of termites are long and slender, in two pairs that are similarly sized and shaped. The name of the termites' order is derived from their having equal wings. The veins near the anterior margin of the wing are prominent with the rest only faintly marked. The wings are quickly shed after flight with a simple body flick when the swarming termites find a new nest site, pair up and dig in. The remnant of the wing is a distinct triangular scale.

Signs of Infestation

The presence of swarmers, wings or damaged wood signals that termites are infesting a structure.

• Swarmers: Generally, the first sign of infestation noticed by homeowners is the presence of swarming reproductives on window sills or near indoor light. Swarmers inside the house nearly always indicate an active infestation in the structure. The presence of swarmers outdoors is a natural phenomenon, but should warn that termites are near and possibly attacking a nearby building.
• Wings: Another indication is the presence of wings, discarded by swarmers as a normal part of their behavior, found near emergence sites, on window sills or in cobwebs. Infestations also can be detected by the presence of shelter tubes going up the sides of piers, utility entrances or foundation walls.
• Damaged wood: Wood damage often is not found initially, but it definitely indicates termite infestation. Any wood-to-soil contact is a potential site of entry into a home. Wood that yields a dull, thudding sound when struck by a screwdriver or hammer should be examined. Careful probing of suspected areas with a sharp, pointed instrument such as an ice pick will disclose termite galleries or damage.

Prevention

Many termite problems can be prevented through sound initial designs, mechanical alterations, and sanitation. The basic premise behind prevention is to deny termites access to food (wood), moisture and shelter.

Planning before construction is vital. Position or modify the building site so that the soil grade slopes away from the structure in all directions. Houses already built may need remedial grading or installation of positive drain lines. Soil-filled porches, patios, sidewalks or breezeways should slope gently away from the house.

Leave at least 2 inches of clearance between soil-filled porches and planter boxes and the house. This spacing does not prevent infestation, but allows free air movement and an opportunity for visual inspection or mechanical control. Planter boxes, if not separate from the house, should be built as an integral part so that termites cannot enter from the soil beneath. The final soil level in the planter boxes should be at least 6 to 8 inches below any wooden structure such as window frames or siding.

Eliminate all wood-to-soil contacts, including attached fence posts, stair casings, trellises and door facings (Fig. 6). Remove these structures from the soil and set them on masonry blocks or replace them with pressure-treated wood. The grade level should be at least 6 to 8 inches below the top of the foundation or wall covering. Although this clearance does not prevent construction of shelter tubes over the foundation, it does allow visual inspection. Separate shrubbery and dense foliage from the house to aid inspection of the foundation line.

A plastic film used to cover at least 70 percent of the area underneath the house may prevent moisture build-up in the subflooring. Place foundation wall vents opposite each other and close enough to the corners of the foundation to provide cross flow ventilation and eliminate dead air spaces. A rule of thumb for the number and size of vent openings is 1/150 of the net area covered by the building.

Wood exposed to constant wetting from rain should be pressure-treated. Wood marked “Wolmanized “ is worth the added cost. Rest wood porches, steps and stair carriages on concrete bases and separate them from the soil by at least 6 inches. Seal foundation openings, such as for plumbing wraps and service utilities, with a good grade of roofing coal tar pitch or rubberoid bituminous sealer. Remove extraneous cellulose material, such as wood scraps or stumps, from underneath and around foundations.

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