What are wood-eating insects?
Behind this adjective are two Greek words: “phage” which means eater And “xylos” which means drink. Under the category of xylophagous insects, we include all those that feed on wood in all its forms. In nature, this will be the branches, trunks or roots of trees, whether living or dead. In the house, the wood-eating insects attack all wooden structures (frames, windows, wooden doors) and furniture. We must not believe that only the insect which has reached maturity is the greatest devourer: these are the larvae which are the most dangerous.
Since wood cellulose is not very digestible, fungi and bacteria in the wood and in their own digestive tract improve assimilation. In nature, they have an important role in the regeneration of forests, but in the habitat, they are real scourges.
A significant invasion of wood-eating insects and their larvae can endanger an entire housing structure if care is not taken.
There are two main categories of these pests in France: termites which are the subject of legislation and are listed by mapped areas specifying the most infested departments in the territory and the insects to be wood-eating larvae (house capricorns, woodworms, lyctus).
What wood-eating insects are present in France?
Whether in your frame or your old or recent furniture, keep your eyes peeled and check if any of the wood-eating insects and their larvae have taken up residence in the wood.
There are several types of wood-eating insects in France:
The house beetle (Hylotrupes Bajulus)
This xylophagous insect has spread since the massive use of softwood in construction after 1945.
It measures approximately 8 to 25 mm as an adult. It is dark brown with two black spots on its thorax. The larvae are more to be feared because they can dig galleries for years (up to 11 years). All softwoods (pine, spruce, fir) are their favorite places and as this wood is often found in the attic, you will have to be particularly vigilant at this level of the habitat.
The wood weevil
This wood-eating insect recorded in France can measure between 2.5 and 5 mm in length. It stands out for its cylindrical body and red-brown color, although it can sometimes also be black. Its larva, creamy white in color and wrinkled in appearance, has no legs.
The eggs laid by the female will hatch after 16 days, then giving way to larvae which will dig tunnels in the wood. Adults do not live more than a year.
The infestation will mainly take place on damp, decomposing wood, although the proliferation of these larvae can then spread to healthy wood in the vicinity.
The small wood beetle (Anobium punctatum)
Very present throughout the national territory, the small woodworm is found mainly in areas where trees have had their bark removed.
It is a small insect measuring approximately 4 mm whose larvae evolve for 5 years in the wood, creating holes. After this period, they come out to reproduce.
Small beetles are not only confined to the outdoors, sincethey are also found in homes where they can infest anything that contains wood : furniture, musical instruments, but also the structures of the home (floor, frames, joinery, etc.).
The large beetle (Xestobium rufovillosum)
This is another wood-eating insect whose length is between 6 and 10 mm and whose larvae particularly like damp and degraded wood. It causes exit holes of approximately 4 mm.
The brown lyctus (Lyctus brunneus)
This wood-eating insect is the one that causes the most damage. It is found in nature but also in homes, warehouses and some museums. It can measure up to 7 mm and be dark brown or slightly red in color.
The larvae are particularly formidable because they nibble the wood from the inside. They are particularly feared in sawmills where they like to infiltrate and cause major damage.
What damage are caused by these pests?
Wood-eating insects are real scourges for homes and other buildings because they can weaken an entire structure. In the most serious cases, a building infested, for example by termites, may even collapse if nothing is done to eliminate the pests.
The invasion of a home by termites must even be reported to the town hall.
When the observation is made by a tenant or a co-owner, they must respectively notify the owner and the co-ownership trustee so that protective measures can be taken.
How to spot the presence of wood-eating insects?
The secret to spotting the presence of these insects is to examine all the wooden parts of the house: frame, beams, furniture, wooden window frames, doors, floors, etc.
Certain signs should alert you such as:
- small holes in the surface of the wood;
- the presence of sawdust;
- wood dust;
- the sound of “gnawing” even slight can be heard near a beam for example;
- “corpses” of these insects;
- visible insects (it is possible to see them when they like to come out into the open air, i.e. over a period from May to October);
- unevenness on the surface of the wood.
If in doubt, you can request a diagnosis from a professional.
What preventive treatments should I use?
To prevent the invasion of these pests in your home, there is no secret: you must use preventive treatments on the elements of the wooden house.
If you had your house built, the wooden frame is installed with a preventive treatment against wood-eating insects which can protect it for around 10 years. Beyond that, it is strongly recommended to repeat treatment using a professional. This uses appropriate treatments and techniques which will provide a barrier to these pests for ten more years.
You can also maintain the frame yourself and treat it using suitable products, that is to say with products containing xylophene. Remember to treat all the elements of your interior that contain wood.
How to get rid of wood-eating insects?
To eliminate wood-eating insects, there are several methods:
The logging
This involves brushing the wood which will eliminate the damaged parts of the wood infested by wood-eating insects. Before brushing, the most important damaged parts on the surface of the wood are removed, brushing and dusting helps to penetrate the xylophene treatments.
The whitewash
This involves applying the treatment using a brush to the entire surface to be treated. Then wait 24 hours before applying a second coat of product for better effectiveness.
Spraying
This is a method that allows you to spray the treatment product on your wood. Here again, make sure to make a second application after 24 hours.
Spraying or whitewashing may be sufficient when treating a small area (around 80 cm²) or in the case of furniture. But when the surface area of a frame or beam is significantly greater, an injection will also have to be carried out.
The injection
To get rid of the larvae which are installed deep in the wood, the best is often to proceed by injection.
As the product is very irritating to the skin and mucous membranes, it is often advisable to call a professional. But if you decide to do it alone, remember to protect yourself with gloves, protective clothing and a mask.
The technique consists of drill holes and inject the product strictly respecting the precautions for use.
When should you call a professional?
Certain preventive or curative techniques may require the intervention of a professional.
- On the one hand, handling products can be dangerous if you do not take certain precautions, on the other hand, certain places can be difficult to access especially if you are not well equipped and the risk of falls is to take into account, especially if you have to work on a frame.
- You should also call a professional when you live in a building and the wood is infested by termites because these insects may have weakened the entire building.
- Finally, when selling a property, the technical file to be given to the client must include a termite diagnosis if you live in a very exposed region. Its validity is 6 months.
To find the right professional, you will need to choose a company with CTB-A+ certification (Technical Center for Wood and Furniture).
Is there any financial aid?
Among the expenses for improving your home, you can claim the maintenance of your home and the use of xylophene products and techniques to keep your home in good condition. These expenses qualify for a tax credit.
In addition, the National Agency for Housing Improvement (Anah) is implementing income-tested subsidies in order to enable low-income households to deal with problems of infestation of their homes by pests.
Wood-eating insects are invaders of our homes and can cause significant damage to structural elements and to furniture and other wooden objects. Fortunately, there are preventive and curative solutions to eliminate them.