Common furniture beetle (Anobium punctatum) can affect timber anywhere but it usually attacks soft wood and likes a small amount of moisture in the timber. The adult beetle lays its eggs in crevices and between timber joints, the larvae hatch out and are too small to see the entry hole. The larvae bore up and down the grain of the timber creating frass in the tunnels they bore.
They digest the starch in the timber converting this to sugars. The period of larvae development prior to metamorphosis into the adult beetle can be from 2 – 4 years.
As the temperature in the environment warms towards summer the larvae bore their way to just below the surface of the timber and create a chamber into which the larvae then change into the adult winged beetle. The beetle then gnaws its way out of the timber leaving a round hole 2 – 3 mm wide with sharp cleanly cut edges and the frass created from the boring of the hole and tunnel leading to it will have spilled, especially if the hole is on the underside of the timber.
The adult beetles crawl or fly towards the light to seek a mate, lay eggs and repeat the life cycle. Successive life cycles if not interrupted by appropriate treatment can cause considerable damage and eventual collapse of timbers.
Common Furniture Beetle
This is by far the most commonly found species of woodworm we find in Ayrshire. Normally about 40 eggs are laid by an adult beetle in small indentations in seasoned wood and they will hatch after about 3 months. These grubs will then burrow themselves into the timber for anything between 3 – 5 years.
Death Watch Beetle
This type of beetle gets its name as it is usually found in church pews and older oak timbers. Generally seen in hardwoods.
Wood Boring Weevil
Only found in woods that have been infested by wood rotting fungi.
When inspecting accessible timbers the entry holes are too small to see. Exit holes means the attack is at least 2 years old. A heavy scattered attack means several life cycles over a decade or more.
Inspections are random and limited to those timbers visible at the time of inspection. Consequently it is not possible with absolute certainty to say that there is no live infestation.
Treatment is via low toxicity insecticide chemicals, which are deposited on the surface of the timber and form a toxic barrier to the wood beetle and the ingestion of which by the emerging adult will act as a stomach poison and kill the insect. Thus control over the continued spread of the attack is immediate and the attack is eradicated over the residual fly out period of up to four years.
Inspections can never cover all timbers – the best that can be done is to examine accessible timbers in damp areas typically to timber floors round the bottom edge of the WC, under baths, in airing cupboards, under-stairs cupboards, loft timbers round the hatch frame, ridge boards rafters etc. under floor areas especially where air bricks are blocked.
Whilst damp is a leading factor resulting in woodworm some species of wood boring insect, such as the Wood Weevil are only found in instances where fungal rot has already begun to occur.