Common pests that attack logs.
Wood Boring Beetles
Wood Boring Powderpost Beetle-
A small wood boring beetle that begins its life on the surface of an unfinished log and burrows in as larvae where they tunnel through the wood eating the starches and nutrients in the wood needed for development. Because they begin as larvae on the surface, finished wood is a great defense against further infestation as the baby larvae do not have the ability to bore through a finished surface. Once in the wood the larvae can spend many years inside before emerging through a round emergence hole with a small pile of dust left as an indicator. True Powderpowder post beetles or lyctid beetle only attack hardwoods generally such as oak, maple and mahogany, so their real threat comes in the form of flooring, hardwood furniture and other hardwood household items.
Exit Holes- Round and vary from 1/32 to 1/16 inch
Frass- Small piles of very fine flour-like wood powder on or under the wood. A slight jarring of the wood makes the frass sift from the holes.
Longhorned beetle or Round Headed Wood Borers (larvae common name)
Longhorned beetles are one of the most common pests that can be found in log homes. They are easily recognized by the long antennae on the heads. Treatment is up to the homeowner as if this is the pest that is affecting your home there is no really good treatment. They do not re-infest a home after their emergence because they will not bore into seasoned wood. Treatment is not recommended.
Exit Hole- 3/16 to 1/4 inch oval
Frass- course and fibrous
Flat-headed wood borers
Adult beetles are sometimes called metallic wood borers because of their showy coloration. The larvae are similar to longhorned beetle larvae, except that the area behind the head is somewhat flattened. Like longhorned beetles these wood borers do not re-infest and thus their potential for damage is limited.
Exit Holes- flattened oval in shape 1/4 to 5/8 inch long oval holes; twice as long as wide.
Frass- Powdery and fibrous
Flat Headed Wood Borer
Another beetle that is often called a Powderpost beetle, Anobiid beetles can infest both hard and softwoods making them a common pest in many infestations. They have a slow productivity time in the infestation so even if a home is infested from the beginning of its life it may not be detected for up to ten years. Anobiids prefer moist areas so thought treatment is possible, moisture prevention should be a number one concern.
Borates are a good treatment for this beetle.
Frass- The frass of most Anobiid beetles contains numerous fecal pellets which are often stuck together in clumps. Look for the accumulation of powdery frass and tiny pellets underneath infested wood or streaming from exit holes.
Exit holes- round and vary from 1/16 to 1/8 inch in diameter.
Old House Borers
They are large insect that attacks softwoods with a life cycle that can extend to 10 or more years with the first emergence five to seven years after construction. Some studies show that they remain in the larval stage up to 15 years. Early signs can be the noise made by older larvae chewing in the wood, especially in the middle of the night when larvae are most active.
Like an anobiid beetle infestation, most structural damage is caused by water infiltrating into exterior emergence holes, thus promoting decay.
Exit Holes- 1/4 to 5/8 inch oval-almost round hole
Frass- Fine powder with small tight packed pellets
Old House Borer
Carpenter bees are bees that bore into solid and decaying wood to create nests. These nests can extend up to 10 inches into the wood and be used more than once. If they are reused they can be made larger and more complex and can house more than one grouping eventually creating tunnels that can reach up to 10 feet into larger timbers.
Exit/Entrance Holes- slightly less than 1/2 inch and perfectly round
Frass- yellowed stained coarse sawdust
Treatment for infestations is generally not that difficult, but more often then not there is a root cause for the problem that involves moisture in the wood. Many wood boring insects search out decaying wood so to truly solve the issue one must replace the wood that is rotting to control the problem. Replacing the infested wood in conjunction with proprer insecticides is the proper way to take care of wood boring insects.