Bugs that bore holes in wood are serious pests which have several effects. They create hazards by damaging the structural integrity of woody trees, making them more prone to breakage. They affect the economic value of woody trees, cause reduced growth rates, and also affect wood-based furniture and items in homes.
About 4,000 species of termites exist worldwide, 10 percent of which are economically significant due to their wood-damaging habits. Termites are differentiated by their feeding habits into soil-feeding, subterranean, grass-eating, drywood and dampwood. The subterranean and drywood termites feed exclusively on wood and are responsible for a lot of wood damage. Subterranean termites live below the ground and come above ground to look for food. Drywood termites live inside the wood as they consume it, sometimes concealing themselves within the wood for years without any outward sign, until the damage becomes too pronounced to hide.
Different species of beetles bore holes in wood, mainly to lay their eggs. Lyctidae beetles are also called powderpost beetles because their larvae create a powdered substance made up of food fragments and feces. After the eggs deposited by the beetles develop into larvae, the wood serves as a source of food for them as they continue to mature. Bark beetles and long-horned beetles bore holes beneath the barks of trees. The Southern pine beetle attacks pine trees, sometimes infesting a healthy tree in such large numbers that they overwhelm and eventually kill it.
The two groups of weevils that are major borers are the palmetto weevil and the cypress weevil. The palmetto weevil is the largest weevil in North America and primarily infects palm species like royal palm and coconut palm. The cypress weevil attacks Japanese cedar, Leyland cypress and pond cypress.
Carpenterworms are the caterpillars of carpenterworm moths. These caterpillars tunnel through the trunks of trees, all the way to the sapwood, as they develop. Signs of carpenterworm infestation include a powdery sawdust-like substance at the points of entry and at the base of the tree. Clearwing moths lay their eggs on trees, near the edges of galls and other types of wounds. When the larvae emerge, they tunnel into the tree, where they continue to feed and develop. Large infestations of the clearwing borers can kill a tree.
Carpenter bees bore tunnels into softwoods like pine, cedar and redwood to lay their eggs. Signs of carpenter bee infestation include the presence of sawdust at the point of entry. These tunnels serve as a nest of sorts, where male and female carpenter bees can winter until spring, when they usually mate.