Subterranean Termites Explained with Life Cycle Detail

Subterranean Termites are the species of Termite to look out for in the Sydney region. Economically, termites cause more damage to timber structures than fire, flood, storm and any other natural disaster, put together…

We cannot overstate how serious the risk of Termite attack is in a major metropolis like Sydney. It just happens they have everything they need, such as moisture and established eucalypts. Termites can be extremely fast at timber destruction, once the colony is established. Colonies are usually in a nearby tree or below ground and can move over 50metres from the nest to consume timber, creating day nests or halfway houses in cavites such as brick veneer or timber frames walls.

Termite damage in NSW homes has been estimated to exist in at least 1 in 5 homes and approximately 30% of homes in Sydney have had some form of Termite activity (building or grounds). The CSIRO has rated Sydney as the 2nd highest risk zone in Australia for Termite attack, second only to the tropics, where termite mounds can be over 2m tall. Economically, termites cause more damage to timber structures than fire, flood, storm and any other natural disaster, put together.

Insurance is available for Australian homeowners to protect against natural disasters, but insurance is not readily available to protect homes against termite attack. Termites are often mistakenly referred to as White Ants, however there are a number of key structural differences between termites and ants. Whilst not everybody’s idea of bedtime reading, termites are an incredibly sophisticated species and their lifecycle and habits are very interesting.

termites under magnifyer

Life Cycle

Termites undergo lifecycle metamorphosis. After the eggs are laid, they hatch into immature forms. These forms then undergo several moults. Upon reaching adulthood, termites become workers, soldiers or either developing alates or supplementary reproductives. Supplementary reproductives then begin to produce their own eggs and form new colonies. Developing alates become winged reproductives and emerge from nests in swarms when conditions are right. When alates land they drop their wings and become dealates. If they can find suitable conditions (food, water and shelter) they will then become king and queen and form a new colony.

Termite casts
Termites live in a colony, which is made up of separate castes or roles. Reproductives, workers and soldiers.

Reproductives include the King, Queen and alates (future Kings and Queens).

The queen of a termite colony can live up to 50 years. Colony can range in size from having thousand of members to hundreds of thousands, some species can produce colonies in the millions. The Queen’s primary role is the ceaseless production of eggs. At the colony’s beginning, the first batch of eggs may only be ten to twenty eggs and these must be attended to by the King and Queen. As the colony matures, egg production may increase to over one thousand per day.

It is the role of the king to fertilise the queen. In the early development of a termite colony, the king carries out the tasks of the worker termites.

Alates are the winged, reproductive caste. When a colony reaches maturity, Alates are formed. When conducive conditions of high heat and humidity are present, Alates are released in great swarms. Alates are the only termite caste that develops eyes, as they are the only caste that intentionally leaves the confines of the colony. Upon landing, the Alate will begin breeding and form a new colony.

Worker termites carry out all the work in the colony and are by far the most abundant member of the colony. Workers are male and female. They are blind, wingless and sterile. Workers carry out the building of the colony. They procure food and distribute it to other colony members, tend to eggs and developing termites and maintain the well being of the colony. Workers possess a thin cuticle and if they are exposed outside the colony, they are susceptible to desiccation (drying out).

Soldier’s role in the colony is that of defense. When a breach is made in the colony the defenseless worker termite’s retreat. Soldiers will then come toward the breach to attack any enemy present and defend the colony from invasion. The worker termites then come up behind the defences of the soldiers to re-seal the breach, often stranding the soldiers outside to die. One adaptation of the soldier caste to deal with its role in defense is to have a thicker head region.

Most species of termites eat grass and other organic decaying matter, however some species infect timbers in service and are therefore considered timber pests. The only member of the termite colony that can actually eat timber is the worker caste. It is the role of the workers to gather food and transfer it throughout the colony.

termite activity gallery 3x3 images

Nest Types

Ground mounds
Many species of termites make ground mounds. These mounds are comprised of a hard outer casing and an inner central core of soft papery material which is the nursery. The temperature within the ground mound termite nest is generally 24 – 30 degrees Celsius, and the humidity is very close to 100%, which presents desiccation (drying out).

Arboreal Nests
Some termite species form large nest sites on the exterior of trees. In many cases although the arboreal nest may be high in a tree, the queen of the colony is often located at the root crown area. Arboreal nests often form nesting sites for cockatoos and other native birds.

Subterranean Nests
Many pest termite species form subterranean nests. These nests can be in trees or tree stumps in sub-floor cavities and beneath bathrooms etc. Termites that forage form subterranean nests may travel large distances and cause damage to structures far from the nest site.