Wood Destroying Insects

Termites
Termites are the most common and most destructive wood-destroying insect. They are most prevalent in warm climates, but can be found in a few localized areas of Canada as well. Termites, like ants, are a social, colonizing insect. Within each colony there are reproductives, soldiers, and workers. The workers are the ones that damage the wood. There are many species of termite; the two most common are subterranean and drywood termites.

Subterranean Termites
Any time wood is exposed to elevated moisture, conditions are ripe for subterranean termite activity. Wood close to or in contact with soil is especially prone to termite attack. The workers build mud tunnels or tubes as a means of traveling between the soil and wood elements. The hidden nature of their activity makes them especially difficult to detect. Often the tunnels are the only visible sign of their presence. Swarming winged termites or damaged wood are also indications of activity. Formosan termites are a very aggressive subterranean termite species that has invaded areas of the southeastern U.S.

Traditional treatment for subterranean termites involves applying a chemical barrier between the house and soil using non-repellant pesticides (termiticides). Termites passing through the barrier pick up the toxic chemical and carry it to the nesting areas where the entire colony is eventually affected. A relatively new approach to termite treatment is baiting. Bait stations are placed around the perimeter of a house; when there is evidence of termite activity at the station, a termiticide is placed in the station. While bait stations may be used proactively, in most cases they are used in conjunction with some form of conventional treatment when an infestation has been confirmed. Surface applied borates are also used for termite treatment. Conventional treatment measures may not be possible in some cases, such as when a well is located within or near the foundation or if the heating system ductwork or piping runs through a floor slab. Formosan termites are a very aggressive subterranean termite species that has invaded areas of the southeastern U.S.

Drywood Termites
These insects are most prevalent in warm southern coastal areas. Drywood termites feed and nest within the wood. They will attack relatively dry wood anywhere in a structure. Signs of their activity include small piles of fecal pellets or partially digested wood. Spot treatment is possible for limited infestations, however, in more severe cases, tenting of the house and fumigation may be required.

Carpenter Ants
The carpenter ant, a relatively large black to reddish-black ant, has become a major infestation problem in many areas. When nesting in old tree stumps or timbers, they often invade the house foraging for food. But they will also nest within a house. They are attracted to moist environments and will gnaw out their galleries for their offspring in solid wood adjacent to a high-moisture area. But unlike termites, they receive no nourishment from the wood they excavate. Carpenter ant damage is generally more localized than damage caused by termite infestation. While treatment for carpenter ants sometimes involves the whole house; in most cases spot treatment using a surface applied pesticide, or even simply removing the source of attraction (moisture), can eliminate the infestation.

Beetles
There are numerous types of wood destroying beetles. Common types include powderpost beetles, wharf borers, and old house beetles. Each beetle has differing physical characteristics such as its size, shape, color, etc. Older homes are generally more likely to experience beetle infestation; however, it is also possible to find infestation in newly milled lumber used for new homes or furniture.

Adult beetles deposit eggs in cracks or holes in the wood. As they develop into the larval stage, they start boring through the wood. After a period of months, or sometimes years, the larvae emerge as adults through "exit" holes. The primary signs of beetle activity are their exit holes and fine sawdust-like “frass,” which may fall from the holes. In many cases, despite the presence of exit holes, the infestation will actually be the result of old activity. Often spot treatment of the infested area or applying a surface pesticide or even paint will prevent a recurrence. In extreme cases of chronic re-infestation, fumigation may be required.

Carpenter bees
The carpenter bee, a large bee that is similar in appearance to a bumble bee, creates tunnels in wood, often in an exterior trim piece, to deposit its eggs. This bee is primarily a nuisance pest, but if allowed to reinfest the same areas, structural damage could occur. The principal sign of activity is the presence of ½-inch diameter holes with stains below. Sawdust piles may also be evident. Spot treating and plugging the holes will take care of most carpenter bee infestations.