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Woodworm Guide: Detection, Causes, and Treatment

Woodworm Larvae lies on a tree

Throughout our professional experience, we have successfully managed numerous cases of wood-boring infestation. A common query we receive from our clients is whether there were any means to detect and address the issue proactively. To assist with this, we have created a comprehensive guide which will delve into the world of woodworm infestation, covering everything you need to know about its detection, causes, and treatment. We will provide expert insights and practical tips to help you identify the signs of woodworm, understand the underlying causes of infestation, and take appropriate measures to protect your property from this common wood-boring pest.

What is Woodworm and what are the common signs of woodworm?

Woodworm refers to the larval stage of various species of wood-boring beetles that can infest and consume wood. An infestation can seriously threaten the integrity and durability of wooden structures and furniture within your property. If left untreated, significant damage can be caused, leading to permanent damage and costly repairs. As a property owner, it’s essential to be well-informed about woodworm and how to effectively detect, prevent, and treat it. 

What exactly is a woodworm? What are the different types of woodworm?

Despite its name, woodworm is not a worm but rather the larval stage of a beetle’s lifecycle. These beetles lay eggs in the crevices and cracks of wood surfaces and once the eggs hatch, the larvae burrow into the wood, creating tunnels as they feed on the wood fibres. The most common type of woodworm comes from the Common Furniture Beetle, but in the UK we can also experience woodworm problems from the House Longhorn Beetle and the Deathwatch Beetle. 

During the larvae stage they feed on the cellulose present in the wood, gradually eating away at the wooden structures, compromising the strength and stability of the structure. Over time, this can lead to weakened wooden beams, joists, floorboards, furniture, and other wooden components, posing risks to the safety and integrity of the affected areas.

What are the tell-tale signs of Woodworm Infestation?

Old log with woodworm holes and burrows created by beatles Anobium punctatum
Old log with woodworm holes and burrows created by beatles Anobium punctatum

Woodworm infestation can be difficult to detect in its early stages, as the larvae typically remain hidden inside the wood, making it a silent threat that can cause significant damage before any visible signs appear. Therefore, understanding the characteristics, detection methods, causes, and treatment of woodworm infestation is crucial for effectively managing and preventing this common wood-boring pest.

The period between April and September marks the woodworm season, during which these pests are most active. Active woodworm infestation can manifest in various visible signs, depending on the stage of infestation and the species of woodworm beetles involved. Some common signs of woodworm listed below can help you identify a potential infestation.

Common signs of woodworm

Woodworm exit holes on wooden surfaces:

These are typically the result of adult beetles emerging from the wood after completing their life cycle. The exit holes are usually about 1-2 mm in diameter and can be found on the surface of infected timber, wooden beams, furniture, floorboards, and other wooden structures.

Tunnels in the wood: 

In addition to the exit holes, you may notice tunnels running through the wood. These tunnels, also known as galleries, are from the woodworm boring their way through the wood as they feed and lead off in sporadic directions.

Fine powdery dust or frass: 

This is the result of woodworm larvae tunnelling through the wood and pushing out their excrement, which appears as fine powdery dust or frass. It can accumulate around exit holes, on wooden surfaces, or in cracks and crevices.

Weak or crumbling wood: 

Infested wood may become weak, brittle, or crumble when touched or tapped, indicating extensive damage caused by woodworm larvae feeding on the wood fibres.

Presence of live larvae: 

In some cases, you may be able to spot the actual woodworm larvae on the wooden surfaces or inside exit holes. They are typically creamy-white in colour, with a cylindrical or curved shape, and can vary in size depending on the species.

Presence of live or dead beetles: 

Adult beetles will emerge from the wood between May and October and you may gradually notice an increase of live beetles crawling over the surface of your wood or in nearby locations. It’s also possible that dead beetles can be found within the timber due to unsuccessfully emerging from the wood in time.

What Does Woodworm Look Like?

Tiny but mighty, the woodworm leave their mark on the wood as they burrow through, creating intricate tunnels and patterns in their wake
Tiny but mighty, the woodworm leave their mark on the wood as they burrow through, creating intricate tunnels and patterns in their wake

Woodworm larvae are the juvenile form of wood-boring beetles and have distinct characteristics. They are typically creamy-white in colour, with a cylindrical or curved shape, and can range in size from a few millimetres to several centimetres, depending on the species. Woodworm larvae have small, segmented bodies with a hard outer shell and are equipped with strong jaws that they use to chew through wood fibres.

What is the lifecycle of woodworm?

Egg Stage:

The woodworm lifecycle begins when the adult beetle lays its eggs in the crevices and cracks of wooden surfaces. The eggs are tiny, about 1mm in length, and are typically laid in batches of up to 50. The female beetle can lay several batches of eggs during her lifetime, depending on the species.

Larval Stage

The eggs hatch into tiny larvae, which are white and worm-like in appearance. The larvae are the destructive stage of the woodworm lifecycle, as they feed on the wood for 2 – 5 years. During this time, they create a network of tunnels and holes in the wood, which weakens the structure and can cause significant damage. 

Pupa Stage

After several years of feeding, the larvae will pupate and transform into adult beetles. The pupa stage can last for several weeks to several months, depending on the species and environmental conditions. The pupae are usually found in the tunnels created by the larvae and can be identified by their yellowish-brown colour. 

Adult Stage

Once the pupa stage is complete, the adult beetle emerges from the wood and begins the cycle again by laying eggs on wooden surfaces. The adult beetles are typically small and brown or black in colour and can fly short distances. Mature adult beetles have a very short lifespan, living only two to three weeks.

How do you detect and identify woodworm in your property?

The wood-boring beetle may be small, but its distinctive markings and iridescent sheen make it a true standout
The wood-boring beetle may be small, but its distinctive markings and iridescent sheen make it a true standout

Detecting woodworm infestation requires a thorough inspection of the wooden structures and furniture in your property. Whilst we would recommend a professional perform a survey of your property to accurately identify all areas woodworm are present, here are some steps to help you effectively detect woodworm yourself.

Detecting Woodworm

Inspect wooden surfaces:

Check for small round exit holes, fine powdery dust or frass, and weak or crumbling wood on wooden beams, furniture, floorboards, and other wooden structures.

Look for live larvae:

Carefully examine the wooden surfaces and exit holes for the presence of live woodworm larvae. They may appear as creamy-white, cylindrical or curved larvae with small legs and distinct body segments.

Check for signs of recent activity:

Look for fresh exit holes, frass, or other signs of recent woodworm activity, as this can indicate an ongoing infestation that requires immediate attention.

Consider environmental conditions:

Assess the environmental conditions in your property, such as high humidity, dampness, or poor ventilation, as these can create favourable conditions for woodworm infestation.

Seek professional inspection:

If you suspect woodworm infestation but are unsure about the extent or severity of the problem, it’s recommended to seek professional inspection and assessment from a qualified pest control expert or a wood preservation specialist.

By being vigilant and proactive in detecting woodworm infestation, you can take timely measures to manage the problem and protect your property from serious damage. In the next sections, we will explore the causes of woodworm infestation and effective treatment options to combat this persistent pest.

Causes of Woodworm Infestation

Delicate and intricate, the woodworm galleries wind their way through the timber, a testament to the tireless work of these tiny creatures as they transform wood into a work of art.
Delicate and intricate, the woodworm galleries wind their way through the timber, a testament to the tireless work of these tiny creatures as they transform wood into a work of art.

Different species of woodworm prefer different types of wood, from hardwoods such as oak and mahogany to softwoods such as pine and spruce. However, there are several common symptoms that can lead to a woodworm infestation. Understanding the causes can help you identify and address the underlying factors that may be contributing to the problem. Here are some common causes of woodworm infestation.

Common causes of Woodworm

Environmental Conditions

High humidity, dampness, and poor ventilation are favourable environmental conditions that can contribute to woodworm infestation. Wood-boring beetles thrive in moist environments where the wood moisture content is high, as it provides them with the necessary conditions for egg-laying and larval development. Wood that is exposed to constant moisture or dampness, such as in poorly ventilated areas, basements, or crawl spaces, can become susceptible to woodworm infestation. Additionally, high humidity levels can lead to condensation on wooden surfaces, creating a moist environment conducive to woodworm activity.

Wood Moisture Content

The moisture content of wood is a critical factor that can influence woodworm infestation. Wood with high moisture content is more susceptible to wood-boring beetles, as it provides a suitable environment for egg-laying and larval development. Wood that is freshly cut, untreated, or stored in damp conditions can have high moisture content, making it more vulnerable to infestation. Wood with a moisture content of 20% or higher is particularly at risk, as it provides optimal conditions for wood-boring beetles to lay their eggs and for larvae to feed and develop.

Acquiring infested wood or timber

When woodworm larvae have already infested an item, they can easily spread to other wooden surfaces in the vicinity. These larvae can remain dormant for long periods until they find a suitable environment to continue their life cycle. Woodworm in furniture can be a silent threat therefore, it is essential to inspect any second-hand wooden items for any obvious signs before bringing them into your home. If you find any signs of woodworm infestation, such as small holes or wood dust, it’s best to avoid the item or to have it professionally treated to prevent the spread of the infestation.

How to Treat and Prevent Woodworm Infestation?

The aftermath of a common furniture beetle attack - a stark reminder of the power of nature to transform even the most solid of structures over time
The aftermath of a common furniture beetle attack – a stark reminder of the power of nature to transform even the most solid of structures over time

If you suspect or have confirmed a woodworm infestation in your property, it’s essential to take prompt action to prevent further damage and protect your wooden structures. There are various methods and options available for treating woodworm, ranging from DIY approaches to professional treatments. Here’s a comprehensive guide on how to effectively treat woodworm infestation:

Woodworm Treatment

If the woodworm infestation is mild and limited to a small area, you may be tempted to attempt treating it yourself using DIY methods. Whilst some common DIY woodworm treatment options can help, they often don’t account for the severe structural damage that has been caused nor the potential spread around the property. DIY methods can be challenging and hazardous to your health so always take every precaution and utilise specialised equipment and protective gear.

Professional Woodworm Treatment

For more severe or widespread woodworm infestations, it’s recommended to seek professional woodworm treatment services. Professional woodworm treatment companies, such as “The Preservation Company,” have the expertise, experience, and specialised equipment to effectively treat woodworm infestations and safeguard your wooden structures. The Preservation Company can provide you with a professional service to eradicate and manage problems with woodworm. 

Some common professional woodworm treatment methods include:

Insecticide Treatments & Surface Treatments:

Professional woodworm treatment companies use specialised insecticide treatments. These treatments are typically more potent and effective in killing woodworm larvae and preventing further infestation. They may be applied as surface treatments, injections into the wood, or fumigation treatments, depending on the severity and extent of the infestation. Surface treatments involve applying woodworm treatment products, such as woodworm killer sprays or preservatives, directly to the surface of the affected wood.


Fumigation is a professional woodworm treatment method that involves sealing the affected area and using fumigants to eliminate woodworm larvae. This method is typically used for severe infestations or in cases where other treatment options may not be effective. Fumigation requires specialised equipment and should only be carried out by trained professionals.

Wood Replacement:

In some cases, severely damaged wood may need to be replaced to effectively treat woodworm infestation. This may involve removing and replacing the affected wood with treated or non-infested wood to prevent further infestation and restore the structural integrity of the wood.

It’s important to note that professional woodworm treatment may require specialised knowledge, equipment, and safety precautions, and it’s recommended to seek expert advice and services from reputable woodworm treatment companies like “The Preservation Company” to ensure effective and safe treatment.

Let a professional deal with your woodworm problem

Our team is on the move! With our fleet of vehicles, we’re ready to tackle any preservation challenge, bringing our expertise and passion for protecting buildings to job sites across the region

The Preservation Company offers a reputable option for the treatment and management of woodworm, with expertise in property care and preservation. Professional woodworm treatment methods can include insecticide treatments, fumigation, or wood replacement, depending on the severity and extent of the infestation. A professional team can handle the whole process, from the initial survey to identify the extent of the infestation, to the professional application of treatments including all aspects of health and safety. 

Woodworm infestation is a serious concern for wooden structures. Early detection, understanding of the causes and appropriate treatment measures are crucial for protecting your property. Whether you seek professional woodworm treatment services or not, taking prompt action can prevent further damage and ensure the longevity of your wooden structures. 

Common Woodworm Questions Answered

Will woodworm spread?
What kills woodworm?
Does woodworm treatment work?
When does woodworm hatch?
How often should you treat woodworm?
Does woodworm fly?
Can woodworm be carried on clothes?
Is woodworm a beetle or a worm?
How much should woodworm treatment cost?
Is woodworm treatment covered by house insurance?
What does woodworm look like?
What causes woodworm?
Will woodworm spread to other furniture?
Will bleach kill woodworm?
When does woodworm emerge?
Do woodworm eat painted wood?
Is woodworm harmful to humans?
Do I need to treat woodworm?
Does woodworm leave dust?
Who Treats Woodworm? 
Is Woodworm Common? 
Where Do Woodworm Lay Their Eggs? 

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Gavin White
About the author

Gavin White

Gavin is an experienced and trusted building preservation and restoration professional with over 40 years of expertise in the field. He is the founder of the Preservation Company, which he established in 2009, and holds certifications in CSTDB, CSSW, and SWD. His dedication to preserving and restoring historical buildings has earned him a reputation as a highly skilled and respected professional in his industry.

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