‘Tis the Season…For Woodworm!

Some interesting facts about the little buggers that want to eat and eat and eat.

Woodboring is thought to be the ancestral ecology of beetles, and bores made by beetles in fossil wood extend back to the earliest fossil record of beetles in the Early Permian (Asselian), around 295-300 million years ago.

Infestations are far more likely in areas with high humidity, such as poorly ventilated loft spaces. Housing with central heating/air-conditioning tends to cut the humidity of wood in the living areas to less than half of natural humidity, thus strongly reducing the likelihood of an infestation. Some species will infest furniture.

The common furniture beetle or common house borer (Anobium punctatum) is a woodboring beetleoriginally from Europe[1] but now distributed worldwide. In the larval stage it bores in wood and feeds upon it. Adult Anobium punctatum measure 2.7–4.5 millimetres (0.11–0.18 in) in length. They have brown ellipsoidal bodies with a prothorax resembling a monk's cowl.

Life cycle

The female lays her eggs in cracks in wood or inside old exit holes, if available. The eggs hatch after some three weeks, each producing a 1 millimetre (0.039 in) long, creamy white, C-shaped larva. For three to four years the larvae bore semi-randomly through timber, following and eating the starchy part of the wood grain, and grow up to 7 millimetres (0.28 in). They come nearer to the wood surface when ready to pupate. They excavate small spaces just under the wood surface and take up to eight weeks to pupate. The adults then break through the surface, making a 1 mm to 1.5 millimetres (0.059 in) exit hole and spilling dust, the first visible signs of an infestation. After they emerge, the adults do not feed; they find mates, reproduce, and die.

The first step in pest control is prevention. Particularly important in this respect is to keep the timber dry - below 16% moisture content. A relative humidity within the building above 60% may lead to an infestation, and timber moisture content below 12% is too dry for an infection to occur.[3] Anobium punctatum normally only attacks seasoned sapwood timber, not live or fresh wood.

Infection, past or present, is diagnosed by small round exit holes of 1 to 1.5 mm diameter. Active infections feature the appearance of new exit holes and fine wood dust or ‘frass’ around the holes.