Subterranean Termites / White Ants
Various species
Family: Rhinotermitidae, Termitidae, Mastotermitidae
Order: Isoptera
Identification:
Termite workers and soldiers resemble ants, but do not have the "waist" of an ant. Most termites are pale in colour, often with a darker head (although there are some pale ants too). Like ants, termites are social insects - they live in colonies. Some species build characteristic mounds, while many others live entirely underground. Male termites have dark, cylindrical bodies and 4 long, delicate wings which they shed after their mating flight. Australian pest species belong to the genera Coptotermes, Heterotermes, Nasutitermes, Schedorhinotermes and Mastotermes (the last in the tropics only).
Distribution:
Australia-wide, but more diverse in timbered and northern (tropical) parts of the country. In Tasmania the only pest termite is one species of Coptotermes. All terrestrial habitats. Pest species are commonly classed as either "subterranean" or "drywood" termites. Subterranean termites live in populous nests in or on the ground, in damp timber or in a hollow tree.
Life history:
Termites feed on cellulose in the form of living or dead plant tissue, such as timber, grass and man-made products like paper and cardboard. They may also damage cables. They live in colonies consisting of one or a few queens assisted by a large number of workers together with fewer soldiers and males. Juveniles are also usually present. Certain, usually stormy weather conditions trigger mating flights in which males and young queens leave a parental nest to mate, disperse and establish new nests.
Subterranean termites need contact with the soil and moisture. Their nests may be visible as a mound, or be concealed underground, in damp timber or in a hollow tree. From the nest, workers make subterranean tunnels, sometimes more than 50m long, to remote feeding sources. Where buildings are attacked there may be more than one entry point. Timbers vary in their susceptibility to attack, but those that are susceptible include both soft and hardwoods. Infested timber is often hollowed out.
Pest Status:
Damage to house frames may be expensive and need costly repairs; in the worst cases the house may be condemned. Subterranean termites are estimated to cost Australia $80-100 million/year in structural damage and associated pest management.
Management:
Termite management consists firstly of keeping the pests away from susceptible structures - prevention is better than the cure. Preventive measures include physical barriers such as stainless steel mesh or crushed stones, chemical barriers applied to the soil or in a fibrous blanket, and/or use of termite-resistant materials such as preservative-treated timber.
Timber pergolas, verandahs and steps should not be in contact with the ground. Do not plant trees, shrubs and climbers against a building, and be aware that nests in mature eucalypts, tree stumps and hardwood sleeper walls are potential sources of building infestations. If the building is on a slab, avoid piling soil or timber against external walls. If the floor is on stumps or brick piers, inspect the "ant" caps regularly for breaches, and make sure no flooring timbers are in contact with the ground.
Where a building is found to be infested, the infestation can be chemically dusted. Locate and treat the source nest if possible. Restore or install physical or chemical soil barriers. Buried bait systems are useful for monitoring and treating infestations. Biological termite control agents such as parasitic fungi and nematodes may offer possibilities in the future.