Termites, sometimes incorrectly referred to as ‘white ants’, are the type of insects that form large colonies and have adopted a social existence.
One consequence of this has been the formation of distinct ‘castes’, where different termites in a colony have different roles, and different structures associated with these roles.
Three main castes occur:
- Reproductives –The reproductive caste of termites includes the queen who controls the entire colony and is continuously laying new eggs to strengthen the population of the colony, the king who keeps the queen fertilized, and the winged reproductives (alates) it is these alates which we see flying en masse on warm humid evenings or mornings with a slight breeze. They are fully hardened individuals, which have long wings that are shed from a basal fracture line after dispersal and are the only sexual mature individuals.
- Soldiers – The soldier caste of termite has the sole job of protecting the colony. They are sterile, have a hard and darker head with large mandibles (pincers) or a long head process, from which adhesive substances are secreted. In some species they knock their heads on the tunnel walls to warn the worker termites of danger.
- Workers – The worker caste of termites is the one that does all the damage to your house. This caste of termite consumes the timber, feeds the rest of the colony, builds the nest and maintains the workings. They are small, pale, sterile individuals that are the most numerous caste present.
It is difficult to identify termites from the de-winged reproductives and the undifferentiated workers, and most identifications are made on the soldier caste.
The three main categories of termite are:
- Subterranean termites (nest in the ground and form mounds, nest inside trees and logs and sometimes have arboreal nests) these are the main economic pest of houses in south-east Australia.
- Dampwood termites (nest in rotting wood on the ground and depend on damp conditions).
- Drywood termites (which do not need moisture and can nest in dry timber).
Members of all categories can be of economic importance because they may attack structural timber or living trees in plantations and commercial forests, and are ecologically important in recycling vegetation and the holes they form in trees can be used by birds and marsupials for nesting.
Some of the aspects of termite behaviour allow us to utilize these behaviours to eradicate colonies and increase the effectiveness of inspections. Termites feed and communicate messages through a process called trophallaxis. This is a process of passing food and messages via the mouth and anus.
Termite colonies may be destroyed indirectly via the introduction of a toxin to a number of the colony population and this toxin will be spread throughout the colony via trophallaxis and mutual grooming. This can be done by baiting, dusting or the application of a non-repellent chemical soil treatment.
From their nests in trees, the pest species of termites make subterranean tunnels that may extend hundreds of metres to reach timber in buildings and often such infestations are not detected until several thousand dollars damage has been done.
Termites are the most destructive insect pests of houses and buildings in Australia. The incidence of infestations has increased from 3% in 1954 to above 30% currently, despite the technical advances in their detection and control.