True Powderpost beetles
are a group of woodboring beetles
in the insect
and the false powderpost beetles, the family Bostrichidae
. These, and other woodboring beetles Anobiidae
, Anobium punctatum
(common furniture beetles
), and deathwatch beetles
), all fall in the superfamily Bostrichoidea
. The damage caused by the family Cerambicidae (the most common is the Old House Borer) is often confused with that of powder post beetles. However the damage is often very old, and of no consequence.
The term "powderpost" comes from the fact that the larvae
of these beetles feed on wood
and, given enough time, can reduce it to a mass of fine powder
. They are therefore considered pests
. The family Anobiidae is the only one capable of digesting cellulose, the primary ingredient of wood, and all other species excrete the wood without digesting it.
Powderpost beetles spend months or years inside the wood
in the larval stage. Their presence is only apparent when they emerge from the wood
as adults, leaving pin hole openings, often called "shot holes" behind and piles of powdery frass below. Shot holes normally range in diameter from 1/32 inch
, (0.8 mm
) to 1/8 inch
), depending on the species of beetle. If wood conditions are right, female beetles may lay their eggs and reinfest the wood
, continuing the cycle for generations. Heavily-infested wood
becomes riddled with holes and rooms or basements packed with a dusty frass — wood that has passed through the digestive tract of the beetles. The larvae feed mainly upon starch in the wood. They leave holes in your wood.
Depending on the species, Powderpost beetles can feed upon certain hardwoods
. Some hardwoods are naturally immune, if they have low starch content, or if the pore (vessel) diameters are too small for the female beetle's ovipositor which prevents her from inserting eggs into the substrate.
Wood preservatives can be used to treat the wood and prevent beetle infestation. The most common treatment uses boron.
Items that can be infested by powderpost beetles include any wooden tools or tool handles, frames, furniture, gun stocks, books, toys, bamboo, flooring, and structural timbers.