True Powderpost Beetle  Family: Lyctidae

Quick Look Pest Stats

Color: Reddish brown – black

Legs: 6

Shape: Narrow, oval

Size: 1/8″ – 1/4″

Antennae: Yes

Region: Found throughout North America



Species found in the PNW include the brown lyctus beetle (Lyctus brunneus), the western lyctus beetle (Lyctus cavicollis), and the southern lyctus beetle (Lyctus planicollis).




Powderpost beetles often attack hardwoods, and can be found in hardwood floors, timbers and crates, antiques and other objects made of hardwood materials.


The lyctids, or true powderpost beetles, feed predominantly on starch in hardwoods, such as oak, maple, or ash, although they also infest bamboo (a grass). Hardwood flooring, cabinets, trim, plywood, and wooden articles, such as furniture, tool handles, and crates, are commonly infested.


Powerpost beetle is a term used to describe several species of small (1/8-3/4 inches long), wood-boring insects which reduce wood to a fine, flour-like powder. Damage is done by the larvae as they create narrow, meandering tunnels in wood as they feed. Newly-emerged adults mate and lay eggs on or below the surface of bare (unfinished) wood. The eggs hatch into tiny larvae which bore into the wood, emerging as adults 1-5 years later, usually during April – July. Homeowners are more likely to see damage than the beetles, themselves, because the adults are short-lived and are active mainly at night. They are attracted to the light.


Some researchers believe that powderpost beetles are second only to termites in the United States in their destructiveness to wood and wood products.


The texture of the true powderpost beetle’s frass is the powdery, unlike the false powderpost beetle’s gritty frass. Infestations are discovered after noticing small, round “shotholes” in the wood surface. These are exit holes where adult beetles have chewed out of the wood after completing their development. 


Protect wood from infestation by painting or varnishing to seal pores, cracks, and holes where these beetles could lay eggs. To keep from accidentally introducing wood-boring beetles into a finished structure, inspect furniture and other objects before bringing them into buildings. Remove and destroy dead tree limbs around buildings or near any area where wood products are stored. For firewood: only bring in what you can burn that day. 


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