How to Identify Signs of Wood Borer
You may not realise that you have a wood borer problem until the resulting damage becomes visible, so early identification is key before they cause more harm.
What Does a Wood Borer Look Like?
There are four stages of wood borer development
- Adult beetle
Adult beetles will lay their eggs in cracks in wooden objects, floorboards and timbers.
When larvae hatch they immediately burrow through the timber, making it very unlikely they would be seen. They’ll be hungry and your woodwork will be their only food source. Safely inside the wood they continue to tunnel and feed for several years.
As the larvae mature and increase in size, they bore towards the wood surface to pupate and emerge as adult beetles.
Fact: Different woodworm insects prefer different woods, which will help you to identify what sort is causing your problems. Some prefer softwoods like pine, spruce and cedar while others like hardwoods such as eucalypt, oak, ash, and mahogany. Whatever the species, all of them will leave some signs, if you have an active wood borer infestation. Find out more about the different species.
Signs of Wood Borer
- Fresh exit holes in timber – round or oval shaped with sharp edges, the holes will appear clean and fresh.
- Tunnels in the wood – also known as ‘galleries’ which are often hard to see.
- Bore dust – (also known as frass) caused by emerging adult beetles, and are usually visible below the infested timber.
- Weak and damaged floorboards – in extreme cases, a foot or chair leg going through the floor can indicate a more serious problem.
- Crumbling wood – around corners or edges to roof joists or floorboards.
- Dead beetles – usually found near the infested timber or around nearby windowsills.
- Adult beetles – emerge from timbers between May and October.
- Eggs – these vary in size depending on the beetle, but all are difficult to spot with the naked eye.
- Wood Borer larvae – usually a creamy-white colour and curved in shape.
Dealing with a Wood Borer Infestation
If left untreated, wood borers can seriously weaken timber – this may lead to structural failure of timbers.
Our professional, experienced surveyors will carry out a thorough inspection to assess the extent of any woodworm problem and the type of wood borer involved. Based on this detailed evaluation they will then recommend any appropriate wood borer treatment.
Wood Borer Species
Wood damaging pests can attack expensive antiques and even a building’s structural components. Wood pests have managed to develop an astonishing variety of life forms, and can even live comfortably in totally dry wood.
Common Furniture Beetle
Much damage caused by wood boring beetles can be attributed to the Common Furniture beetle. Its natural habitat is the broken branches of trees and areas where the tree bark has been removed.
Adult beetle is 3 – 4mm in length.
Larva will live for 3 – 5 years boring through timber before emerging to breed.
- They actively fly in warm sunny weather.
- Within homes and other buildings the furniture beetle is an exceedingly common pest.
- Despite its name this beetle can invade more than just furniture.
- Infestations can damage decorative woodwork, musical instruments, wooden tools and on a more serious scale wood flooring, joinery and structural timbers.
- These wood boring beetles consume hardwoods and softwoods.
House Longhorn Beetle
- Adult beetle is 8 – 25mm in length.
- Black/brown colour with greyish hairs and 2 black spots on thorax which resemble eyes.
- Larvae tunnel between 3 to 11 years before emerging.
- Flight holes between 3mm and 7mm.
- Infests seasoned and partly seasoned softwoods; pine, spruce and fir most susceptible.
- It is frequently timbers used in the roof space that are infested.
- Damage can often be severe in timbers around the chimney area. The larvae produce large amounts of bore-dust (or frass) containing cylindrical pellets. Sometimes this is visible in the ‘blistered’ appearance of the surface wood.
- Longhorn beetles will fly freely in hot, sunny weather which enables them to spread an infestation from one building to the next.
Powder Post Beetle
This beetle infests hardwood timber in service such as Eucalyptus, Oak, Ash, Elm, Walnut, Sycamore, Sweet Chestnut and African Mahogany. It attacks these wide-pored hardwoods because the female beetle is able to fit her eggs into these pores.
- Adult beetle 4 – 7mm in length.
- Red/brown in colour.
- Adult beetles usually appear in the summer months, but in heated premises they can be found throughout the year.
- The larvae gradually reduce the infested timber, just leaving a thin veneer of wood on the surface.
- Emerging adults make pin-hole sized openings 1 to 2 mm in size, often called ‘shot holes’.
- Whole lifecycle is completed in about one year.
- Primary pest of timber yards.
- Given enough time, wood will be reduced to a mass of fine powder that crumble to the touch, hence the name ‘powder post’.
- The Bamboo wood borer has a dark brown body which is plump, almost cylindrical, and is 2 to 3.7 mm in length.
- The antennae of the Bamboo wood borer broaden at the tip, with the last 3 segments considerably larger and ending in well-defined antenna clubs.
- The humped thorax of this wood borer conceals the head and has teeth-like indentations in its rounded front. Two large dimples at the back of the thorax.
- Elytra (wing cases) are covered with small pits and bristly hairs.
- The female Bamboo wood borer lays 27–35 eggs into the food substrata. Its larvae hatch and bore into the plant.
- Larva undergoes up to 4 development phases and pupates inside the plant.
- The lifecycle of the Bamboo wood borer can be as short as 60 days in good conditions (35 °C, 75% relative humidity) leading to multiple generations per year.
- The Larva feeds on bamboo cane, but the weevil is also known to breed on cassava root.
- Larva makes tubular passages along plant fibers and emerges leaving a perfectly round hole.
- This species of wood borer is originally from East Asia, and was brought in with cargo on ships (e.g. tapioca products), wooden packaging and even wooden musical instruments.
- The adult Bark Borer is 3–6mm in length and is red or chestnut brown with yellow silky hairs on its’ body.
- The female Bark Borer lays 20-30 eggs in bark crevices which hatch into larvae in two to three weeks.
- Pupation follows in spring or early summer, lasting one or two weeks.
- Adult Bark Borers emerge between May and August.
- Damage is confined to unbarked softwoods, causing no structural damage. Damage caused by these species of wood borer insects occur on pergolas, rustic work, fence posts and garden sheds.
- Adult Deathwatch beetles are 5 to 7mm in length; where the larvae are 10mm in length.
- These wood borer beetles are dark reddish brown and have yellowish scale-like hairs on the upper body and wing cases. The larvae are a creamy white hook-shape covered in golden hairs with dark brown jaws on its head.
- After mating, the female Deathwatch beetle lays 3-4 eggs clustered in cracks of rough wood surfaces. They are whitish, oval shaped and she lays between 40 and 60 during her life. The eggs hatch within two to five weeks.
- The larvae pupate just below the surface of the wood. The adult Deathwatch beetle emerges in early summer by gnawing through the surface and leaving the characteristic exit holes.
- In its natural environment, this wood borer insect lives in the dead wood of several species of hardwood trees where fungal decay has set in.
- Within buildings, the deathwatch beetle occurs almost entirely in old hardwood, in particular large oak timbers.
- The larvae cause the most damage, as they tunnel in the wood for a period of between five and ten years.
- The Wharfborer is 7–14mm in length.
- This species of wood borer is yellow brown in colour. The tips of elytra (wing case) are black.
- 3 ridges along the length of the elytra.
- Eggs of this wood borer are laid on damp, decaying timber.
- Larvae bore through wood for about 9 months then emerge in summer.
- Larvae require wood to be constantly wetted so that fungi break down the wood fibers.
- Two main sources of Wharfborer infestation in buildings are structural timbers where rainwater leakage occurs, and pieces of timber buried below concrete foundations, paths and pedestrian precincts.
Wood Boring Weevil
- Adult Wood Boring Weevils are 2.5 to 5mm in length.
- The weevils are reddish brown to black. They have a long snout, a cylindrical body and short legs.
- The larvae are creamy white C-shaped, wrinkled and legless.
- Eggs of the Wood Boring Weevils are laid singly by the female in specially evacuated holes. They are glossy, white, flexible and flattened at one end. They hatch within 16 days.
- The larvae tunnel in the wood for between six months and a year. They pupate near the surface for between two to three weeks.
- The adult Wood Boring Weevil emerges in the summer by boring its way leaving exit holes. The adults may live for over a year.
- Damage caused by the Wood Boring Weevil is associated with damp and decaying wood, particularly timber already rotted by cellar fungus. Infestations can spread to adjacent healthy wood.