Powderpost beetle is a term used to describe several species of small insects that reduce wood to a flour-like powder. They are right behind termites in their ability to damage dry, seasoned wood.
|Color||The adult is reddish brown to black. Larva is nearly white.|
|Size||Adults are 1/32 - 1/4" long depending on species. Larvae are up to 1/4" long.|
|Appearance||Adult has a long, narrow and flat body with sides almost parallel; antennae with 2-segmented clubs; wing covers are often with rows of hairs. Larva is C-shaped, with enlarged thorax, short 4-segmented antennae and legs with long claw.|
Powderpost beetles are wood destroying insects and eat wood cell contents, mostly starch with some sugar and protein. Like termites, some powderpost beetles will feed on hardwoods — such as oak, ash, walnut, bamboo and hickory — and softwoods like pine. As the frames from most homes are built from softwoods, certain species of powderpost beetles can cause structural damage to houses. While you may not see structural damage from these species, it is possible to discover infestations in wood paneling, crown molding, window and door frames, plywood, hardwood floors or furniture.
Powderpost beetles breed in dead and dried hardwoods such as the dead branches and limbs of trees. They enter lumber while it is being stored and cured, and emerge from the finished product.
Adult powderpost beetles are active at night, fly well and are attracted to light.
A typical female lays 15-50 eggs in exposed wood pores, cracks and crevices but never on wood that is painted, polished or waxed.
The larvae tunnel in sapwood along the grain packing their tunnels loosely with very fine, powdery flour-like dust.
After several molts (2-9 months), the mature larva bores back near the surface to build a chamber and pupate.
The adult bores out to the surface to exit and mates, doing very little feeding.
Development time from egg to adult is 9-12 months, but can be as little as 3-4 months, or as long as a few years. This life cycle can up to five years to complete, meaning larvae can be eating the wood in your home for years.
Prevention & Control
- Rough-cut lumber should be kiln-dried to kill all stages of the beetle life span.
- Sand and varnish all wood so the adult beetles cannot find crevices in the surface to deposit their eggs.
- Do not store items in outdoor buildings such as barns and sheds because they are often infested with wood-boring beetles.
Infested wood should be treated immediately with a product made especially for powder post beetle control. Wetting the wood first will increase efficacy of the product, helpful given the long life cycle of the beetle and the wood is often very dry.