"Vrillette" in French actually covers two unrelated insect families: one bores into roof timber for years unnoticed, the other settles into an opened flour bag within weeks. Confusing the two means treating the wrong problem.
Woodworm: small holes and fine dust
The common furniture beetle (Anobium punctatum) is the most frequent wood-boring species in Belgium. Larvae live inside the wood for 3 to 4 years before emerging as adults, leaving small round holes 1-2mm wide and fine beige dust (frass) on the floor or furniture.
The deathwatch beetle (Xestobium rufovillosum) mainly attacks wood already weakened by damp or fungus — its presence often signals a more advanced structural issue, particularly in old beams.
A clean, sharp exit hole inside indicates recent activity; a greyish, worn hole may date back years with no active infestation.
Biscuit beetle: a pantry insect
The biscuit beetle (Stegobium paniceum), also called the drugstore beetle, attacks dry goods: flour, biscuits, spices, stale bread, pet food. Unrelated to wood despite the similar French name.
Typical signs: small brown insects 2-3mm long in an opened package, silky threads, clumped grains, sometimes tiny holes in the packaging itself.
Treatment is entirely different from wood treatment: identifying and discarding contaminated goods, thoroughly cleaning cupboards, and monitoring storage areas — no injection or brushing involved.
Why the confusion is common
The common French name "vrillette" covers dozens of beetle species with very different lifestyles. Searching by symptoms (small holes, brown insect) without specifying wood or pantry easily leads to the wrong advice.
A simple test: if the insect or holes are on a wood structure (roof timber, beam, old furniture), it's woodworm. If they're in or near a dry food item, it's the biscuit beetle — two problems, two solutions.
Heat treatment: effective on both, not always applicable
Heating to 55-60°C for 30 minutes kills larvae, eggs and adults without chemicals — applicable to furniture or heat-resistant packaged goods, not to timber already in place.
On roof timber or joists, pressure injection of insecticide into the galleries remains the most durable professional method, complemented by surface brushing of exposed areas.
When to call a professional
For wood: as soon as holes are numerous, recent (clean edges) or affect a load-bearing part — the real extent of an infestation is only reliable after inspection, visible dust doesn't always reflect the depth of the problem.
For pantry infestations: if it persists despite cleaning cupboards, or keeps coming back — a hidden source (crack, kitchen cabinet) can escape a standard clean-up.
Frequently asked questions
Does the biscuit beetle attack wood?
No. Despite the similar name, it's a dry-goods pest (flour, biscuits, spices) unrelated to the wood-boring species that attack timber and furniture.
How do I know if woodworm is still active in the wood?
A recent exit hole has clean, sharp edges; an old one is greyish and dull. Fresh dust under the wood signals ongoing activity.
Is an over-the-counter product enough against woodworm?
On a light, localised infestation, a surface treatment can limit spread. On roof timber or joists, only pressure injection reaches larvae deep inside the galleries.