How to Get Rid of Powderpost Beetles

The first thing to do when attempting to get rid of powderpost beetles is to reduce the wood's moisture content to less than 20%. Moisture meters can be used to determine the moisture level in the wood.

Central heat, vapor barriers, and adequate ventilation can also help control moisture and eliminate powderpost beetles. Rough-cut lumber should be dried in a kiln to kill all stages of the beetle. Reducing moisture may not be enough to get rid of powderpost beetle infestations completely.

Sanded and varnished wood will not be as attractive to adult powderpost beetles. They can not penetrate or find cracks and crevices in the wood surface to deposit their eggs.

Don't store valuable items in sheds and barns. Wood-boring beetles are common in these areas.

Infested furniture made of unfinished wood (unvarnished, not painted, not waxed, or not sealed) can be treated with Tim-bor or Boracare. Boracare and Timbor will prevent newly hatched powderpost beetle larvae from entering the wood. Infested furniture that can not be treated with a product like Tim-bor and Boracare can be treated in fumigation chambers. Fumigation chambers are used to fumigate infested furniture. Look for pest control operators that are licensed for fumigations.

If practical, remove infested wood. If not, use residual borate insecticides such as Boracare or Timbor. Due to its long life cycle (12-18) months in the wood, you may see emerging powderpost beetles emerge even after treatment. The eggs and coming larvae will come in contact with the insecticide to kill them.

Identify

Adult Powderpost Beetles do little damage to wood structures, it is the larvae (woodworms) that do most of the damage. They go through a complete metamorphosis: adults, eggs, larvae, and pupae. You can easily recognize the work of powderpost beetles.

When the adults emerge, usually in June, some species leave small holes about the size of a pin on the wood's surface; others make holes the size of pencil lead. Fine and powder-like, a brood of larvae (woodworm) carry on their destructive feeding from these holes.

Usually, these insects have a 1-year life cycle; this means that the adults will appear only once each year. And because of this habit, the larvae have a feeding period of many months.

Larvae (woodworm) are white and cream-colored, shaped with dark brown heads. Larvae create tunnels in the wood and become pupae.

The larvae are curved and wrinkled. Their diet is dependent on the starch in the wood; they are more common in softwood but can attack hardwoods. They require 6-30% moisture content in the wood and complete the average life cycle in one year.

Biology, Diet, and Habitations

The diet of these beetles is sugar, starch, and protein found in the sapwood of hardwood. They attack woods with high moisture. The moisture content of less than 6% is ideal for keeping these beetles from attacking.

In the United States, the True Powderpost Beetle is the most common. They are often found in structures that have been built from infested lumber. They can re-infest if you do not kill powderpost beetles correctly.

How to Inspect for Powderpost Beetles

You need to determine if the infestation is active before initiating treatment to get rid of powderpost beetles.

These products kill exposed larvae and prevent re-infestation when the eggs hatch and immature larvae begin to penetrate the wood. However, the most effective way to get rid of powderpost beetle infestations is to fumigate using sulfur fluoride or methyl bromide.

The surface of unpainted or otherwise unprotected wood can be treated by injecting the galleries with disodium octaborate tetrahydrate such as BoraCare or Timbor.

These products kill exposed larvae and prevent re-infestation when the eggs hatch and immature larvae begin to penetrate the wood. However, the most effective way to get rid of powderpost beetle infestations is to fumigate using sulfur fluoride or methyl bromide.

Wood-boring beetles damage

The first step to management is deciding if there is an active infestation. If you spot powderpost beetle damage, you may be inspecting old damage.

An active infestation will have borings in piles accumulated on the floor below or near the holes. You may also hear a ticking sound made by the larvae. If the damage is old and not currently active, you do not have to treat it.

Inspect all exposed wood surfaces periodically and probe them for evidence of internal damage. Evidence of attack is more common in attics, crawl spaces, unfinished basements, and storage areas.

Again, make sure that the infestation is active (not old damage or old frass). There should be fresh frass the color of newly sawed wood or live larvae or adults in the wood.

Recently formed holes and frass (sawdust-like) are light in color and clear in appearance; old holes and frass are dark in color. If the damage you find is an active infestation, we have listed the best ways to get rid of powderpost beetles below.

The good news for homeowners with hardwood floors is that most of the hardwoods attacked are not commonly used for interior floors, woodwork, or trim. Most of this species does not reinfest wood after it is seasoned, so the damage is limited to that inflicted by one generation. However, the speed of the damage can be considerable.

Powderpost beetles are often found in oak, firewood, and furniture.

1. Deathwatch Beetle

The adult deathwatch beetle, Xestobium rufovillosum, is 1/4 to 3/8 inches long and is gray-brown with patches of pale hairs on the body's back.

The Death-watch beetle is found throughout the United States. It attacks building timbers in poorly ventilated areas where moisture tends to collect. These beetles are heard at night, making an audible ticking sound. It picked up the nickname "Deathwatch" from this behavior.

2. Furniture Beetles

The furniture beetle is found mostly in the eastern half of the United States. Furniture beetle adults emerge in the spring from cells just below the surface of the infested wood. Soon afterward, mating occurs, and egg-laying begins.

When development is complete, the adult powderpost beetle bores directly to the wood's surface, emerging through a round hole 1/16 to 1/8 inch in diameter. Development under ideal conditions can be completed in one year; however, two to three years are common.

The adults are active at night. Some species are attracted to light.

Powderpost beetles commonly infest seasoned sapwood of hardwoods and softwoods. They attack structural timbers, lumber, cabinets, and furniture. These beetles reinfest and the female beetles usually lay eggs in the wood from which they emerged. The larvae typically follow the grain of the wood when feeding ad fill their tunnels with wood frass. The frass is a fine powder with long pellets loosely packed into the galleries.

3. Long-Horned Beetles or Round-Headed Borers

Most representatives of this family infest and feed on dead or dying trees. However, many feed on living trees. Some of these species begin their development in dying trees, logs, or unseasoned lumber and then complete the development as the wood seasons.

Adults vary in size from 1/2 inch to 3 inches long. They can be easily distinguished from other beetles by their long, thin antennae, which may be longer than the body; hence the adults are called long-horned beetles. The adults of these Borer beetles will emerge from the wood after it has been incorporated into the structure. They will not re-infest the wood because of its dryness.

4. Old House Borers Beetles

The Old House Borer is one of the most common in the powderpost beetle family. Its larvae hollow out galleries in seasoned softwood(pine). It is found in older buildings but is more frequent in newer buildings (in houses less than ten years old). The powderpost beetle is well established along the Atlantic Coast, but infestations have been reported as far as Louisiana and Minnesota.

A long life cycle, paired with the fact that powderpost beetle larvae do extensive feeding without breaking through the wood's surface, means that you need to inspect beetle infested wood very carefully to detect old house borer damage.

Rough wood being examined should be probed or struck to detect weakness or the presence of boring dust. If exit holes are present, they will be broadly oval and about 1/4-3/8 inch in diameter. When wood has been infested with fungi, powderpost beetle larval development is faster. Their powder (frass) in the tunnels is like sawdust, tightly packed.

Prevention of Wood Boring Beetles

Most of the procedures that prevent wood infestations are completed before you purchase it, it is the responsibility of those who harvest, mill, or treat the wood. However, those who use wood should take precautions to reduce the chances of infestation in structures and furniture. Using these preventative measures will make it easier to eliminate powderpost beetles in the future.