How to recognise wood-boring insects

Wood borers are not the only insects that attack wood, they are just the most common. Wood is an organic material and is a food source for a number of insects known generically as wood borers. They attack standing trees, freshly felled trees, timber that has become lumber, and even ready-made furniture or wood flooring. They live and thrive under the bark or inside the wood, making holes and channels of various shapes and sizes. All this 'work' causes disruption of the grain, making the wood less resistant. The holes are also a gateway for water to enter the wood and the fungi that cause rot.

Insects are very resistant and it sometimes takes long and aggressive treatments to get rid of them. If the infestation is advanced, burning is often preferred to treatment, because the risk of eggs or larvae remaining inside is very high. But there are all sorts of modern treatments that make it possible to save wooden objects in the home, especially old and valuable ones.

What are xylophagous insects (small wood-eaters)

The xylophagous insects are divided into: beetles, wasps, butterflies, ants. To know how to distinguish them from harmless ones, we need to recognise them. Let's take them one by one.

Wood beetles

Wood beetles are the best known category of wood-boring insects and include carii, designers and ipidele. About cari we have spoken on several occasions, find information aboutdevelopment, recognition and care treatments, anti-caries solutions and natural treatments against them.

Cwood turners are so called because of the specific noise they make. Between 10 and 30 mm long, sometimes even longer, they are easily recognised by their long antennae, in the form of knotted hairs that extend beyond the length of the body. They mainly attack standing trees, but they are also found in timber or lumber, sometimes left over from the life of the tree.

The development cycle is like that of a curry - egg, larva, nymph, adult - and can last between 3 and 6 years, sometimes even 10 years. The galleries formed in the wood are large, oval in cross-section, up to 40 mm in diameter and filled with large sawdust (not fine dust like in curries), even small pieces of wood. There are more than 26,000 species of croaker in the world that live and feed mainly on organic matter from plants, most of them in the tropics. Several types live here, the best known of which are the large oak, small oak, beech and willow tree sapsuckers.

The great oak tailor (Cerambyx Cerdo) is 30 to 50 mm long, black, with reddish-brown antennae at the tip. It has 3 pairs of legs and an oval body, wider towards the head. On the head it has antennae much longer than the body, and at each grip it has a sharp tooth. Lives only in the stem oak. The little tailor (Cerambys scopolii) is very similar to the large one, but is only 18-28 mm long. It is found in the stem of the oak, but also in plum, fag, elder and other trees and shrubs.

Beech tailor (Rosalia alpina) is spectacular, with a beautiful greyish blue colour, 2 pairs of black stripes on the body, interrupted in the middle and a spot on the top of the body, near the head. The antennae are long and streaked with black. Length is between 20 and 35 mm. The larvae develop mainly in old beech trees, and adult beetles are frequently seen in beech forests in the mountains from June to September.

The tailor of the willow (Aromia moschata) also looks special because of its metallic amber-green colour, sometimes with blue reflections. It is 20-30 mm long, with antennae longer than the body but shorter than those of the beech or oak crocus and brown in colour. The larvae find a favourable environment in the trunk willows old, and the adult is often seen from June to August on the tree or surrounding flowers. The adult insect is also recognised by its distinctive musky odour.

Ipids are of two types: bark beetles and wood beetles. Bark beetles are forest pests that spend their lives between bark and wood and can be very dangerous. They can jeopardise the sap supply to the tree and the tree begins to dry out and crack, the wood decreasing in value. One such beetle is the large bark oak of the spruce tree (Ips typographus). Wooden beetles are small insects that tunnel between the bark and the wood along the bark. They can be recognised by the fine wood flour that falls down the tree. The danger is that, if the tree is not debarked after felling, they will make galleries in the wood, thus reducing its value.

Viespile

Viespile are also popularly called sawflies or saw wasps. They are so called because females have saw-like teeth at the end of the egg-laying organ. They use them to tear the wood apart and lay their eggs indoors in the shelter. Along with the eggs, fungi are laid with which the larvae live in symbiosis, but which can be very harmful to wood.

There are many species of wasps, but the most feared is the large wood wasp or the resinous wood wasp (Urocerus gigas or Sirex gigas). It is very similar to a common wasp in colouring and the elongated shape of the abdomen ending in a needle, and the length of the adult insect is 30-40 mm. It lays its larvae inside standing trunks and on freshly felled or wet trunks. Attacks all coniferous trees - pin, molid, brad, larch - but downed spruce trees are the most prone to infestation. The larvae can stay in the wood for 2-5 years before they develop into adults, which means that they can only be discovered when felling or, in the case of atimber, even after it has become asteria or beam. By the time it has emerged from the wood as an adult and taken flight, the damage is already extensive and action must be taken quickly.

Butterflies

In fact, it is the butterfly larvae (caterpillars) that make clean galleries in standing trees, jeopardising their stability in the wind. The best known are the red willow scourge (Cossus cossus) and the ash tree's dotted scrubber (Zeuzera pyrina).

Red willow weevilnot only "slashes" the willows but also the oak, ulmul, alum, frasin, birch or the plum tree. It is large, with a wingspan of up to 70-95 mm. The wings are grey-brown with fine transverse black stripes. Caterpillars have red stripes on the back, black head and 8-10 cm long. They live in the trunk for 3-5 years, after which they emerge forming large holes 1-1.5 m above the ground. The red willow leafhopper loves moisture, both in the wood and the environment.

The ash tree's pointed nipper is also called the wood leopard butterfly because of the black spots on its whitish-grey wings, which can reach a wingspan of 35-60 mm. The larvae stay inside the tree for 2-3 years after which the butterflies emerge from under the bark. It is a tree pest - olive tree often the target of attack - but it doesn't avoid tree species such as willow, teepeethe beech, the oak, the elm. In fruit trees the attack can jeopardise production.

Ants

In general, ants are useful to forests. Some species, however, can do great harm to trees. Likeblack forest ant also called the wood ant (Camponotus ligniperda). The ants live in colonies on the trunk of resinous trees, but also on oak, preferring trees with mould at the base. They attack standing and fallen trees equally. On living ones they climb up to 10 m high, making up-and-down paths and gnawing galleries in them. They also do great damage to the woodland creatures that feed on the ants and their eggs as they destroy wood, hollowing it out, looking for them. So the trunks are damaged and the wood is damaged defects in wood or even drying the tree.

The black ant is one of the largest and most aggressive ants. The queen can reach 16-18 mm and the workers between 7 and 15 mm. It has a black head and a reddish-brown body, a colour that runs down its three pairs of legs. Colonies reach 7000 members, are active day and night, more intense in summer and less in autumn.

The black ant can also be a problem for wet, unprotected wood in the structure of household outbuildings. When such mounds are discovered, chemical treatments must be applied immediately because the wood can be damaged and structurally weakened. It is very important to we protect wood against water and environmental factors and dry it out because humidity favours ant attack.

How wood becomes infested and what causes infestation

The main factor behind insect attack is wood moisture. The wetter it is, the more pleasant it is and the easier it is to attack. This is why wood should be used properly dried, and if drying is done naturally, it should be protected and protected from such attacks. Wood used outdoors must also be protected against water and moisture, and construction solutions must allow water to drain and air to circulate so that the wood dries quickly after rain.

Many problems occur because the wood is left on the wet ground for a long time after felling or the bark is not removed. There are many insects under the bark of the tree, which after felling tend to burrow as deep as possible into the trunk, digging galleries that alter the structure. Quick peeling, cutting and drying protects the wood not only from splitting but also from insect attack.

Unfortunately, we often discover infestation when the wood has already been used in a project. In this case, it should be treated immediately to stop the spread to other objects. The infested item should be thoroughly inspected because the large and deep galleries produced by the insects can damage it. resistance. If the attack seems large, it is better to change it. Unfortunately, it is the wood used in construction that is most affected by large insect attacks and therefore all the more dangerous. One solution is to treat it preventively before use. Also, if used indoors avoid moisture build-up, condensation and mould. These are factors that weaken the strength of wood and create a breeding ground for insects andxylophagous fungi.

I hope you find the above information important. Any additions are always welcome. And if you have any questions or queries, please leave them in the space below. I will certainly answer them.