Main traits and habitats
Termites are socially organised insects, with pronounced differences between their social classes, known as castes. They build their nests in wood or on the ground. Cellulose, a compound they are able to digest, is their main food source, so they attack wood and paper.
The termites develop through a gradual metamorphosis, passing through egg stages, various nymph stages and adults of different castes (workers, soldiers, primary and secondary reproductive castes).
They prefer places of high humidity as they dehydrate quickly under dry air. Therefore, when looking for a place to build a nest they take into account the fact that it will be a hiding place, provide a humid environment and protect the insects from their natural enemies.
Subterranean termites (Reticulitermes and Coptotermes sp) cause a variety of damage to building structures, poles and even living plants. Nests are underground in places where they find the desired degree of humidity.
They build vertical tunnels that resemble clay tubes and which are used to transport food and to protect the insects. Winged forms reach a length of about 1.5 cm, workers and soldiers 1 cm. Termites need specific environmental conditions to thrive. They require a high degree of humidity for survival as they dehydrate easily when exposed to dry air.
Subterranean termites have a strong negative response to light and a preference for warm, humid environments. For this reason, colonies establish themselves deep in the soil where they find the necessary humidity. They need to be in contact with the soil in order to survive. In terms of feeding, subterranean termites prefer wood that is rotting. They therefore attack dead plant material, as well as paper and wood in contact with the soil. They do not usually attack living trees.
The ways in which termites penetrate buildings are diverse; any small crack is enough to start the invasion in search for food. They build galleries in search of nourishment. Their constant mobility is an obstacle to the fight against this pest, and the only way to control its spreading is by placing a chemical barrier.
Subterranean termite inspection
When a termite infestation is first suspected, the pest control professional must diagnose whether or not the pest is there. The detection of a swarm and / or loose wings on the floor, as well as the visualization of vertical mud tunnels near exterior and interior walls, are clues to a termite infestation. Note that this phenomenon occurs only once a year, in spring, which is why infested sites are often overlooked. However, the destructive activity remains active all year underneath or inside ceilings and walls.
The termites work by drilling into the wood, leaving only a thin surface layer that covers the internal hollows. When this layer breaks, they cover the communication with the outside with a material similar to the one used to build tunnels (a mixture of faeces, earth and spit) and that has the appearance of clay.
The holes made by the termites can be detected by striking the wood and listening to the sound produced by the blows or even by soldiers located inside. Old/abandoned tunnels are brittle and dry while new ones have a more humid appearance.
Treating the soil
Treatment consists of applying a chemical barrier to the soil, by means of injection, adjacent to and below the building, in order to prevent the movement of termites.
Non-ground termites are divided into drywood termites, wetwood termites and spraying termites.
Drywood termites generally feed and build their nest in dry wood with a low moisture content. They do not need any contact with the soil to live, unlike subterranean termites. They can cause serious damage to wooden furniture.
Termites enter wood through a crack or crevice, either in the joint between two pieces or inside the space underneath paper that is covering the wood. A male and a female enter the wood they choose as a nest and seal the circular entrance of about 3 mm, excavating behind it a chamber where the queen lays her first eggs. The nymphs that emerge from these eggs do the work of the colony and then become soldiers and breeders.
There is no defined worker caste. During the swarming season, the nymphs make round holes through which the breeders come out. Afterwards, the holes are plugged as well as the entrance one. In the wood these termites dig large chambers that communicate with each other by small tunnels, structures that they keep clean.
The excretion capsules are one of the ways to distinguish these termites: they are hard and have six concave lateral surfaces. Only the ends are round, while those of some wood boring beetles that also excrete capsules from where they live have convex surfaces.
While dampwood termites include some larger termites, wetwood termites do not need any contact with the soil but rather need wood with a high degree of moisture. They are usually found in association with decaying wood. They dig large galleries just like drywood termites, but do not keep them clean. Capsules are therefore found along the tunnels found in infested wood.
Spraying termites live in dry wood. They enter the wood and dig galleries just like drywood termites. However, these galleries are not clean, but instead contain the dust that they turn the wood into. They are much smaller than drywood termites and the fecal capsules are also smaller.
Control of non-underground termites
Treatment of non-ground termites involves either fumigation of the structure (large infestations) or treatment of the wood ( spot infestations). Fumigation is a very specialised procedure that should only be carried out by professionals. Wood treatment basically consists of drilling into the infested wood up to the galleries dug by the termites and forcing the insecticide to disperse through the galleries or using equipment to inject a fumigant into the galleries. In low-level infestations, powders or aerosols are generally used. After inserting the insecticide, the holes should be covered.