Wood Borer and Powder Post Beetle: How to Tell Them From Termites

By Nick, Active Termite Control, licensed pest controller (NSW licence 5074559), Earlwood. Updated 20 October 2026.

Wood borers are beetles. The adult lays eggs in timber, the larvae tunnel through the wood, and when they're grown they chew their way out through the surface. What you see is the way out: small round holes, and fine dust underneath them.

Termites are a different problem altogether. They come up from the soil, live in a colony, and hollow timber out from the inside while leaving the surface intact. Telling the two apart is the first thing to sort out, because the response is completely different.

Borer or termites?

The quick test: holes and powder point to borer, mud points to termites. Ant frass is different again: fine, black and dusty.

If you're not sure what you're looking at, send me a photo through the pest photo check. It gives a likely answer. A sample or an inspection confirms it.

The signs of wood borer

• Round exit holes. Small, clean, round holes in the surface of the timber.
• Fine dust under the holes. The larvae push dust out as they tunnel and exit. It collects in small piles directly under the holes.
• Fresh dust coming back. If you clean it up and new dust appears under the same holes, there's still activity.
• Soft or crumbly timber around a cluster of holes, in bad cases.

The two borers you'll hear about in Sydney

Powder post beetle (Lyctus)

According to the Queensland Government, powder post beetles attack only the sapwood of hardwoods, not softwoods like pine. Their dust is smooth and flour-like, in small piles outside the timber, and the exit holes are about 1 to 2 mm across. (Queensland Government: powderpost beetle)

Furniture beetle (Anobium)

The Queensland Government says the common furniture beetle mostly attacks old pine that's been in service for 20 years or more. Attack is worst in damp areas like flooring and skirting boards, and its dust is packed loosely in the tunnels or pushed out through the holes. (Queensland Government: common furniture beetle)

So borer holes in old pine point away from powder post beetle, which doesn't attack softwood, and towards furniture beetle.

Why I usually replace the timber

I can spray for borers. But 99% of the time I recommend replacing the infested timber instead. Replacing it removes the damaged timber and the borers in it in one go.

What it involves depends on where the timber is. A few floorboards or a section of skirting is a small job. Structural timber in a subfloor or roof needs a builder or carpenter.

Borers aren't part of a general pest treatment and are quoted separately. Call me and I'll come and look.

Is it wood rot instead?

Soft, crumbly timber with no holes and no dust is often rot, not insects. Rot comes from moisture, usually a leaking gutter, downpipe, roof tile or plumbing.

Wood rot can't be treated. The timber gets replaced and the moisture gets fixed. Spraying won't help.

White powder along the skirting?

This one came from a homeowner in Hurlstone Park in October. She had a fine white line of powder running along the joint between the skirting and the floorboards. She'd cleaned it up, and it kept coming back. She was worried it was borer.

It wasn't borer. Two things ruled it out:

• Borers leave piles, not lines. The dust falls in small piles under each exit hole. It doesn't spread out in a line along a joint.
• Borers don't usually come through polished boards or painted skirting. A finished surface like that isn't where they come out.

The likely causes were something else:

• Plaster dust. A crack in the ceiling or the cornice above lets fine plaster dust fall and settle along the edge of the room.
• Damp. Moisture in the wall or subfloor can show up as mould or salt along the base of the wall.

The check: look up. If there's a crack or flaking in the cornice or ceiling directly above the line, it's very likely plaster dust. If the ceiling is sound, damp is next on the list, and that's worth a closer look with a moisture meter.

I offered to come and have a look. If you've got the same thing and you're not sure, send me a photo or give me a call. The photo check now recognises plaster dust too.

What to do if you find borer signs

1. Don't panic. Borer damage happens slowly.
2. Take a photo of the holes and the dust, with a coin beside them for size.
3. Note what the timber is: floorboards, skirting, furniture, structural timber, hardwood or pine if you know.
4. Clean up the dust and see whether fresh dust comes back.
5. Get it looked at. I'll tell you whether it's borer, termites, rot or something else, and whether the timber needs replacing.

If there's any chance it's termites, don't break the timber open further. Book a termite inspection. Inspections are from $330 single storey or $350 two storey, and I check borers and rot as part of the same timber pest inspection.

Common questions

What do wood borer holes look like?
Small, clean, round exit holes in the surface of the timber, with fine dust in little piles underneath.

How do I tell borer from termites?
Holes and powder point to borer. Brown mud and mud tubes point to termites. Termites hollow timber from the inside and leave the surface intact.

Can wood borers be treated?
I can spray them, but 99% of the time I recommend replacing the infested timber. Replacing it removes the damaged timber and the borers in it in one go.

Is borer covered by a general pest treatment?
No. Borers are quoted separately. Call me.

What's the white powder along my skirting?
If it's a line along the joint that keeps coming back, it usually isn't borer. Borers leave piles under holes. Look up at the cornice for a crack: plaster dust is a common cause. Damp is the other one.