Powderpost Beetles

Powderpost beetles bore into hardwoods and structural lumber, leaving small round exit holes and piles of fine, flour-like frass. In Whidbey crawl spaces and older homes, they are a leading wood-destroying pest and a sign of favorable moisture.

How to identify powderpost beetles

Small reddish-brown to black beetles, 1/8 to 1/4 inch, that leave 1/16-inch round exit holes. The telltale sign is talcum-fine frass sifting from the wood.

Behavior & season on Whidbey & Fidalgo

Females lay eggs in wood pores; larvae tunnel for months to years before emerging. Higher-moisture wood is more susceptible, so our damp crawl spaces and unconditioned framing are prime habitat.

Why powderpost beetles are a problem

Repeated generations can progressively weaken flooring, subfloors, and framing. Because larvae work unseen for long periods, damage is often advanced before the exit holes and frass appear.

Signs of powderpost beetles activity

• Tiny round exit holes in wood
• Fine, flour-like frass beneath the holes
• Damage concentrated in crawl-space framing and subfloor
• New frass indicating active infestation

How Salty Dog treats powderpost beetles

We assess the extent, treat affected wood, and address the crawl-space moisture that sustains them so future generations lose their ideal conditions. Learn more about our Powderpost Beetle Treatment service, or browse the full Pest Library.

Frequently asked questions

How do I know if the infestation is active?

Fresh, powder-fine frass and clean new exit holes indicate active beetles. We can help confirm whether emergence is ongoing.

Why do I have them in my crawl space?

Powderpost beetles favor higher-moisture wood. Damp, poorly ventilated crawl spaces are the most common place we find them here.

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