A significant threat to wooden furniture and structural timber, the common furniture beetle is one of the more challenging pests to recognise and treat.

Wood borers can be a damaging pest of certain timbers in buildings. They represent one of the more difficult jobs in pest control – detection, treatment and prevention are all challenging.

One particular borer, the common furniture beetle (Anobium punctatum), presents a problem in coastal areas of Australia, where temperatures are even and humidity is relatively high – ideal conditions for wood-boring insects. The furniture beetle can severely damage pine flooring, panelling and furniture, although it rarely attacks roof beams due to the higher temperatures in roof voids. Like hardwoods, radiata pine is susceptible but less frequently infested, with wood-borers preferring Baltic, New Zealand and hoop pine. The furniture beetle typically attacks timber that has been in service for 20 years or more, as newer timber tends to be treated with preventative agents.

For pest managers, early detection is the key, although this is very challenging. An adult female borer beetle will lay her eggs within susceptible timbers, the eggs then hatch into grubs (larvae, commonly called ‘woodworm’), which feed on the starch content of the timber. The borer larvae will readily eat along the timber grain, creating a network of tunnels – all the while remaining out of sight, undetected. When the larvae have pupated and become adult beetles, they exit the timber through flight holes made in the timber’s surface.

surface damage on old log
Visible Anobium surface damage on an old log

Often, these flight holes are the first indication of borer infestation in a property. The size of the exit holes and texture of the dust (frass) emitted will enable a pest manager to identify the species of timber borer and assess its potential to cause further damage to susceptible timbers. Furniture beetles make a round 2mm diameter hole in the timber surface, surrounded with a fine and gritty frass.

Common furniture
beetle, Anobium

In cases of significant damage to structural timber, the timber may be significantly weakened and an assessment by a suitably qualified builder or structural engineer should be carried out. It is generally impossible to tell whether damage is the result of previous or active infestations and so it should be assumed that the area is still active and be treated accordingly.

Glenn DuBois of Fumapest Pest Control has experience of treating borer damage in homes across Sydney. “Often by the time the damage is noticed it’s too late and the borers have vacated the timber,” he said.

When borers have been identified, Mr DuBois recommends the application of a permethrin-based residual insecticide. “For infested timber in buildings, it’s important to penetrate the timber – and solvent carriers assist in this process,” Mr DuBois explained. This will kill any eggs and larvae remaining in the timber and offer residual protection from future infestation.

Fumapest recommends using Bayer’s Perigen Defence Insecticide to eradicate borers. Solvent carriers can cause staining of the timber, so Mr DuBois is careful to do a small test before proceeding with the entire job to ensure the customer is going to be happy with the final outcome.

“If surfaces to be treated are varnished, the timber must be fully cured before Perigen Defence is applied,” Mr DuBois said. “So it is possible to eliminate borers from timber, but it is important that the owner of the building is aware of the preparation required, the potential effect on the timber finish and the possibility of damage already done before proceeding with the application,” he advised.

Perigen Defence is registered to control furniture, auger and powder post beetles as well as pinhole borers on timbers in buildings. Bayer’s Crackdown Insecticide is similarly registered for use against these beetles (not pinhole borers) but is also registered for use on freshly felled and sawn timber, making it a useful option for those looking to safeguard timber against early infestation.