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INFORMATION BULLETINS
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Wood Damaging Insects


Termites are often the first insects we think of when it comes to wood damaging insects, but there are others that can have a devastating effect on homes too.

CARPENTER BEES -- Although they can be a nuisance outdoors when they fly around you, they can wreak havoc in wood. They are not social insects with only one generation per year.

Carpenter bees bore a very clean cut, almost perfectly round, hole into wood about a half inch in diameter often from the bottom straight up one or two inches and then off to the sides at a 90 degree angle for about 4 to 6 inches. Sometimes, these tunnels that run in the same direction as the grain of the wood, can be up to 10 feet long depending on the number of bees using them. Sawdust is often present below the entry hole and sounds from their boring can sometimes be heard from within the wood. It is here that they lay their eggs, unlike bumblebees that nest in the ground. The carpenter bees hole boring process is fairly quick, making topical, or surface, pest control a difficulty as they typically have done their damage to the wood before those pesticides can take hold. Generally, the damage caused by a couple of bees is not that great, but if used by many more bees the damage can be considerable over the years.

Carpenter bees are very similar in colouring and appearance to bumble bees. One notable difference is that their the upper surface of their abdomen is black and shiny without any hairs. Males, with their whiter looking heads tend to fly around aggressively, but are harmless since they don't have a stinger. The black headed females are not aggressive and don't tend to sting either. Adult male and female carpenter bees winter within their old nest tunnels and mate in the spring.

Carpenter bees prefer unfinished and weathered softwoods like redwood, cedar, or pine. Finished or pressure-treated wood can be less susceptible to their boring. They often bore holes to nest in window frames & trim, soffits & fascia, siding, wooden shingles / shakes, decks and outdoor furniture.

CARPENTER ANTS -- Unlike termites, carpenter ants do not eat wood. Instead, they tunnel through wood while building or expanding their nests. As a result, they throw out discard their wood debris and fecal matter from their nests, an indication when looking for their nest. They also tend to follow the grain of the wood excavating the softer annual rings of the wood first. The damage caused by carpenter ants can look very similar to termites but to the trained professional, signs of their excrement can tell the difference. Carpenter ants are social insects that live in colonies.

Outdoor nesting sites include tree holes, tree stumps, logs, standing dead trees, and planter boxes. When conditions are suitable, carpenter ants may establish nests indoors. Indoors they tend to nest in structural wood, wall voids, attic areas, insulation (foam or fibreglass), hollow doors, window & door casings, voids beneath kitchen / bathroom cabinets, as well as hollow decorative beams. Typically, they are most active at night but you can find them during the daytime too. With some larger mature infestations you may actually hear them. Close inspection of your home is recommended.

Carpenter ants prefer wood with high moisture levels. Due to their relatively small size, these ants can enter a home almost anywhere such as cracks in the foundation or around window and door openings. They may travel use trees and shrubs that are up and against the roof area to get into attic areas. Outdoors, they will often collect water dripping from taps / downspouts or from the condensation that forms on air conditioner refrigerant lines. Inside, they enjoy areas near dishwashers, sinks, tubs or showers.

WOOD BORING BEETLES -- After termites, wood boring beetles are often considered the most significant wood damaging insects in a home.

Powder Post Beetles -- these are easily recognized by the holes the adults leave when they emerge from wood. They have a life span of about 1 year typically with the larvae feeding for many months. They got their name because the wood they feed on is eaten into a very fine powder. There are three common families: Lyctidae, Anobiidae, and Bostrichidae.

(1) Lyctus beetles (sometimes referred to as the "true" powder post beetles) feed primarily on hardwoods. Usually they are brought into buildings via lumber stored outside. Females lay their eggs in the crevices or ends of the wood. When the larvae hatch they bore holes into the wood. After they grow into a mature adult they bore an exit hole through the wood. Hardwood floors in new homes are often attacked.

(2) Anobiids tend to infest on softwoods, such as conifers. With many types of anobiid beetles, very few infest wood. Only the larvae feed on wood. Generally, they prefer wood with higher moisture levels located in cooler locations. Their boring techniques are the similar to lyctid beetles.

(3) Bostrichid beetles generally, cause considerably less damage in homes than lyctid or anobiid beetles. Often, they bore into freshly cut hardwoods and rarely softwoods. Unlike lyctid or anobiid beetles, both adults and larvae of the bostrichid beetle damage the wood. Adult females bore "egg tunnels" into wood to deposit their eggs. After hatching, the larvae tunnel into the wood to feed and grow.

Old House Borers -- These insects belong to a group of beetles called cerambycid. They are also known as long-horned beetles. Most are woodborers in the larval stage. Generally, the old house beetles infest softwoods such as pine. Although they are found in old houses, they are actually more commonly found in new homes. Like other beetles, the larvae penetrate the wood to feed but may not emerge immediately as adults. When they do exit, they too bore holes in the wood.

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