The types of woodworm and how to get rid of it
A woodworm is not a wood worm. It is a collective name for a variety of wood-eating beetles. These beetles lay their larvae the on wet and warm wood. As a larva it eats its way on a span of 1-7 years before these larvae turn to pupae then unto full-pledge beetles. Tiny little holes in a piece of wood are the only tell-tale signs of woodworm infestations. Old wood, new wood, straight or bended wood furniture are the common "eating" grounds of woodworms. Upon maturity, the grown beetle emerges from the wood leaving holes that it bore as its exit point. The mature beetle emerges primarily to mate and then lay eggs on cracks and crevices of any wood surface. The cycle repeats itself.
Kinds of woodworms
A woodworm is not a species as it is actually the larva of wood-boring beetles. There are different classes of wood-boring beetles but the most common that are found in the UK are:
- Common furniture beetle (Anobium punctatum) - The adult common furniture beetle is about 2.7 to 4.5 mm in length. Its elongated body is coloured brown and has a dorsal that looks like a monk's hood. The common furniture beetle is peculiar because it only eats sapwood. This class of beetle does not like heartwood. Because it normally takes 3 to 4 years before adult common furniture beetle exits from its burrow, it is therefore quite difficult to tell if there is actual infestation when buying timber. This beetle's grubs prefer damp floorboards and old furniture.
- House Longhorn beetle (Hylotrupes bajulus) - This beetle could either be black or brown with tiny spots that look like eyes. It has greyish hair on its wings and body. The holes made by a longhorn beetle are larger than the ones made by the common furniture beetle. It prefers to attack the sapwood of softwood timber framing which could result to structural weakening of the house.
- Deathwatch beetle (Xestobium rufovillosum) - This wood-boring beetle makes ticking or tapping sound heard from the rafters on quiet nights, thus the name deathwatch beetle. This beetle prefers very damp conditions preferably decaying with wet rot. It prefers European hardwood like oak, chestnut and ash, preferably softened with decay. The larvae tunnel to the centre of the timber so that it's harder to tell if there is actual infestation.
- Powder post beetle (Lyctus brunneus) - This beetle is found in starchy wood with big pores for the female to lay its eggs in. This beetle is small and is usually reddish brown to black. Normally found in timber yards the powder post beetle does not enter treated, painted or varnished wood. However it can be found in plywood and some sports equipment.
How to Spot Woodworm
Woodworm can cause a lot of damage to your house, structural-wise. Its larvae can eat through your wood beams, rafters or floor joists. Woodworm usually bore holes through wood to exit and mate from the months of May to September. If you see holes on wood surfaces and you suspect woodworm infestation, block the woodworm holes with masking tape or by painting the holes with emulsion in winter. By spring or summer, you can check if the masked holes were disturbed. Other tell-tale signs of woodworm infestation are if there are small round holes in the wood's surface. The holes are akin to the holes in a dart board. If there is fine powdery dust around these holes (frass) then there's a high probability that there is woodworm infestation. See if the edges of the suspected wood have crumbly edges. If there are adult beetles present in your house or have emerged from the holes, then it is likely that there is woodworm infestation.
Treatment Options for Woodworm Infestation
If you have found evidence that there is indeed woodworm infestation in your house, the first thing that you should do is not panic. Not all woodworms are harmful so it's best to identify what kind of woodworm has infested your home. If identifying the woodworm is beyond your capability better get a qualified pest control person to identify and eradicate the problem. If the infestation is quite massive, consult a timber specialist to see if any structural timber has been affected. There are instances where the woodworm infestation is no longer active. If this is the case, then it is also advisable that you get the opinion of a timber specialist too.
There are three options on how to treat woodworm infestation. The first method is by the surface application of pesticides. There are chemicals in the market today that serve as insecticide/fungicide and wood preservative in one. This type of chemical is effective for all hole-boring insects. It can also be used as a preventive option for woodworm infestation.
The second treatment option is fumigation. This option is best suited in "smoking out" deathwatch beetles in large structural timber. However, a spot injection of pesticide on affected timber would also be an effective method to destroy deathwatch beetles.
The third option is freezing which is only suitable for items of furniture infested with woodworm. The piece of furniture is taken to a walk-in freezer and left there for a certain number of days. Sub-zero temperature will kill the woodworm.
Chemicals to kill a woodworm infestation are best done by a trained pest exterminator. To discourage woodworm infestation you can do the following:
- Keep wood well-ventilated and at low level of humidity. There are gadgets that you can use to check the timber's moisture.
- Remove infested wood and furniture to avoid contamination.
- Install electric fly traps at places suspected of woodworm infestation. The electric fly trap will kill any emerging adult beetle and therefore further stop it from breeding.