Death watch beetle infested log

What is a Deathwatch Beetle?

1 May 2019

A Deathwatch Beetle is one of a number of wood boring insects that are found in the UK which are commonly classed as ‘Woodworm’.

Deathwatch Beetles are chocolate brown in colour and grow to around 8mm in length making them almost 3mm longer than the most common type of woodworm being found in the UK – The Common Furniture Beetle (Anobium Punctatum).

Deathwatch Beetle has a variegated appearance as a result of having patches of ‘yellowish’ hairs.

In keeping with other varieties of woodworm, Deathwatch Beetles emerge from timber during what is known as the emergence period which tends to be from mid-March through to the end of June.

deathwatch beetle

Why is it called Deathwatch Beetle?

The reason for the name of deathwatch beetle is that it was often heard when people were “on watch” with an ill person who was on the verge of death.

The beetle is also distinctive with the ticking or clicking sound it makes when it bumps its head against the tunnels it is boring through in the timber or old furniture.
Timber showing signs of Deathwatch Beetle infestation

What Damage is Caused by Deathwatch Beetle?

Deathwatch beetle tends to almost always favour hardwoods, such as oak or elm.

Often the timbers infested are showing some existing signs of decay as a result of white rot (Donkioporia expansa). Deathwatch beetles have also been known though to attack softwoods if they are suffering from rot and in contact with already infested hardwood.

The damage caused looks very similar to that caused by the Common Furniture Beetle although the exit holes are larger in appearance. This is to be expected as Deathwatch beetles are larger in size. The exit holes in the timber are approx. 3mm – 4mm in diameter.

Often around the exit hole, you will see ‘frass’ which will be bun shaped and is visible to the naked eye. The presence of frass is also a tell tale sign of woodworm. The damage within the timber takes the form of extensive tunnelling which weakens the integrity of the timber.

Deathwatch Beetle Affecting Converted Barn in Kent

There was a particular case where Timberwise was contacted by the owners of a timber-framed converted barn in Ashford to survey the timbers within the property. The barn is set in over an acre of stunning gardens and countryside and dates back to the 19th Century. The current owners were looking to sympathetically modernise and convert the barn into a family home.

They were concerned they had a woodworm infestation as a result of spotting several small exit round exit holes in the timber and fine powdery dust around said exit holes. This is a classic tell-tale sign of an infestation of woodworm.

The Timberwise Surveyor inspecting the barn conversion suspected of having a woodworm infestation held the Certificated Surveyor of Timber & Dampness in Buildings (CSTDB) qualification and upon inspecting the timbers, it became clear who the culprit was as a result of the visible damage – Deathwatch beetle.

The Deathwatch beetle infestation had affected all of the structural timbers within the barn. In most cases, woodworm beetles can be treated with an insecticidal spray applied to the timbers.

However, in this case the damage caused by the deathwatch beetle was so severe that parts of the timber were treated with resin-based timber repairs and some parts needed replacing altogether with new timber.

Although discovering a woodworm infestation was not in the plans for the client’s large scale renovation project, with the customer’s patience and Timberwise’s expertise the barn was eradicated from Deathwatch beetle and transformed into a beautiful bespoke home.

How to Get Rid of Deathwatch Beetle

To get rid of a Deathwatch beetle infestation it’s always best to call in the experts to evaluate the situation. A general woodworm survey must be carried out by a qualified timber specialist in order to ensure that the culprits are correctly identified.

Only through correct identification of the beetle can the right treatments be carried out. The surveyor will also inspect the property to identify the size of the infestation and the type of woodworm beetle.

The surveyor will also check to see at what stage of the lifecycle the wood boring insect is in – it may be that the damage is historic and therefore requires no further treatment.

The level of repairs needed will be assessed and a specification put together for any woodworm treatments deemed necessary to be carried out on the infected areas of timber.

For peace of mind, an assessment will be made to see if there are any other property care issues associated with infestation such as dry rot or damp.