Termites In Australia - Information, Inspections & Treatments
“The chances of your home coming under termite attack are greater than flood, fire and natural disaster combined. And yet, termite damage is not covered by your standard home insurance!”
Estimates by CSIRO and other leading bodies estimate that as many as 1 in 5 homes are likely to suffer a termite attack and this may be as high as 1 in 3 homes in high risk areas. Protect your home and investment by having a termite management plan for your property.
Termites or White Ants?
Although they may look like ants, termites aren’t ants at all. In fact they are an ancient group of insects more closely related to cockroaches than ants.
Key ant characteristics:
- Well-formed eyes
- Bent antennae
- Obvious “waist”
- Hard cuticle
- Tend to be brown or black
Key termite characteristics:
- No visible eyes (on workers)
- Straight antennae (“string of beads”)
- No obvious “waist”
- Soft cuticle
- Tend to be pale or white (heads may be darker colour)
Termites live in colonies that can contain anywhere between a few hundred, up to a million individuals (depending on the species). They go through incomplete metamorphosis, with egg, nymph and adult stages.
They form complicated societies with the different castes performing different roles within the colony. The queen lays the eggs, workers care for the nymphs and carry out the foraging, specialised soldiers protect the colony, and reproductives are the new kings and queens who fly off to start new colonies.
There isn’t actually such a thing as a baby termite. The queen lays eggs and the young which hatch are called nymphs, which look like miniature versions of an adult. The nymphs are unable to care for themselves and are fed by adult workers. Nymphs will typically go through 3 or 4 moults before developing into an adult worker. Some of these nymphs will develop into soliders or reproductives – the new kings and queens.
Worker termites live up to their name and do the majority of the work in the colony – looking after the queen and young, building and maintaining the nest and most importantly carrying out the foraging. Workers are made up of sterile males and females (workers in bees and ants are only made up of sterile females) and typically live for between 1-2 years.
Soldier termites are the specialised caste that protect the colony from predators, typically other insects, especially ants. They have modified heads which utilise a variety of defence mechanisms, which vary depending on the species. Some have powerful jaws, other use latex to gum up attackers, others use their heads to plug up entry holes and a few have heads that actually explode! Because of their modified heads, they are unable to feed themselves and are reliant on being fed by the workers. The appearance of the soldier is key feature used in species identification. Soldiers also live for 1-2 years (if they do not die “in the line of duty” earlier!).
Termites with wings, technically called primary reproductives, are the new kings and queens produced by mature colonies. They will leave the colony on warm humid nights, taking to the wing in large numbers in termite swarms.
There are two types of reproductives. Primary reproductives are the new kings and queens produced to found new colonies. These winged termites (alates) pair up during the mating flight. On landing, their wings fall off and they move off together to find a suitable site to start a new nest. Unlike workers, these alates have darker, harder cuticles and obvious eyes.
In certain circumstances and in some species, secondary reproductives may be produced. These are capable of reproducing / laying eggs, but are lighter in colour than the primary reproductives and never develop wings. Typically secondary reproductives may be produced:
- When the primary king or queen dies
- In certain species to allow the colony to grow faster and reach maximum size
- In species that create satellite colonies which may exist away from the main nest
The queen is the most important individual in the colony, producing the eggs to maintain and grow the colony. In some species the queen becomes enlarged (up to 30 mm long) and turns into an egg laying machine capable of laying over 1000 eggs per day. In such species the queen is immobile and resides in a central nest chamber in the colony. Queens can live for over 20 years. However, as they age they become less productive. As this occurs and if she dies, secondary reproductives (queens without wings) can also lay eggs. In some species, they will also retain some of the winged termites (primary reproductives) to support the egg laying or take over completely if the queen has died.
Subterranean termites, which include the main pest species, normally nest underground, which can make the termite nests very difficult to locate. Often the nest will be in the root crown of a large tree (the area between the roots and the base of the trunk). However, some species create an obvious mound on the ground, which obviously makes them a lot easier to spot. And indeed a few species also build arboreal nests (nests in trees). However, even in these arboreal nests, they still need to have contact with the ground, which is achieved through mud tubes on the outside of the tree, or moving within the tree itself.
More photos information on Australian termite mounds.
Nest in the root crown of a tree
Coptotermes acinaciformis mound in the Northern Territory
Arboreal (tree) nest
Termite foraging behaviour
Termites live in large nests. For subterranean termites (the main pest species in Australia) this is generally underground or sometimes in trees. For drywood and dampwood termites, they live in the wood they are consuming. Many species have one main nest, although if they are feeding at a food source a long way away from the main nests, they will often set up satellite nests or bivouacs.
Some species create multiple nests which all orginate from the same original colony. Schedorhinotermes commonly have multiple nests as part of the same colony, making it very difficult to get compete control of infestations. Similarly extensive drywood termite infestations tend to consist of multiple small sub-nests as they exploit the food source.
Termites don’t like to travel. It’s far safer and more efficient to find a food source close to their nest. However, they are perfectly capably of travelling up to 100 m from their nest to a food source. And with over 80% of homes in Australia estimated to be within 25 m of a colony, it is very likely your home is within range of a termite nest!
Termites have a soft cuticle which makes them very susceptible to drying out. It’s one of the reasons they tend to attack areas of home which have a moisture problem. They prefer to travel underground, but when they need to come above ground to access a food source, they need to protect themselves from drying out and from predators. The mud tubes provide a nice, humid highway, protected from predators!
For the same reason, they will sometimes completely cover a food source with mud sheeting, so they can feed underneath, safe and sound.
They will also bring mud into walls and structural wood elements of buildings. Not only does this help to keep their environment moist, but they use this mud as structural support so they can go about eating your home without it collapsing (at least for a while!).
Termites eat cellulose. The main pest species eat wood, but will also cardboard and papers (which are made from wood and contain cellulose).
Some species, such as the cathedral termites in the top end of Australia, don’t cause any damage to homes as they are grass harvesters and other species actually use plant material they collect to grow a fungus, which they harvest and eat.
However, although they only eat cellulose material they can cause damage to other materials and are known to chew through cabling. In addition, their activity and their habit for bringing in mud and moisture to electrical areas can cause electrical problems and even house fires.
They are one of the few animals that can digest cellulose and they can do this due to the unique microbes in the termite gut. These gut microbes vary between different species and are considered one of the main features that drove their evolution.
There is certainly a random element to the way termites search for food. Often the nest will be established near a large food source, but when they start searching for food, they generally do so in a random manner fanning out along foraging paths in all directions from the nest. However, moisture is one of the biggest drivers in determining which way they go – a dry soil is a tough environment for a worker. For this reason, areas of moisture or sites of water leaks tend to be the more likely entry points around buildings.
In the natural environment, wood feeding subterranean termites are attracted to moist soil which is a bit cooler than the surrounding area. Such an environment would be created by a fallen tree… or a building… your home!
Why they attack one home and not another is not just a question of luck. Buildings are actually designed to prevent termites gaining entry without being noticed. So, IF the building and been constructed correctly (with appropriate termite protection) and IF the property owner hasn’t made any modifications (to home or garden) to create a weakness in this design and IF the property owner gets regular inspections, the chances of them getting in without being noticed and causing damage is very low. The chances of a termite attack are reduced further if the areas around and under the building are kept dry.
If they are attacking your home it means there is a weakness in the design (a potential entry point) and a source of moisture (leak or drainage problem). Regular inspections and good home maintenance are musts.
Termite workers typically consume around 5% of their body weight in wood per day. Although this is a tiny amount of wood, when you have a million or so workers in a large colony, a large nest attacking your home can easily consume 100g or wood per day. Over the course of a year that’s 36.5kg or wood, which starts to become a significant amount of damage. Find out how they worked out how much termites can eat.
If they continue eating un-noticed for a couple of years, the damage is likely to be so severe that the home may need to be demolished. Even from the “average” termite attack, damage repair bills of $10,000 and above are quite common.
The giant northern termite, Mastotermes darwiniensis, found in the Northern Territory, some northern parts of Western Australia and Queensland, is a different beast altogether. They are significantly larger than other pest species (workers are 12 mm long v 7 mm in the largest of the other pest species), can exist in colonies of several million and have voracious appetites. Homes that come under attack from the giant northern termite can be all but destroyed in as little as 6 months!
Types of termites
There are several hundred termite species in Australian but only a few species are responsible for most of the economic damage to buildings and crops. The pest species are commonly split into three groups: subterranean, drywood and dampwood termites.
Subterranean termites include all the most common pest species in Australia. Although Mastotermes darwiniensis, is considered the most destructive termite, in terms of speed of damage, it is the Coptotermes species that cause the most damage in terms of dollar value across Australia.
Researchers sometimes refer to “lower” and “higher” species. This really refers to how “primitive” the species is in their colony structure and physiology – how close they are to the primitive cockroach-like termites that developed millions of years ago. The lower termites are considered more primitive and the higher termites more advanced.
Mastotermes darwiniensis considered among the more primitive species.
Coptotermes, Schedorhinotermes and Heterotermes species belong to the Rhinotermitidae family and although are some of the more recently evolved species, there are still considered to be “lower” termites.
It is the Termitidae family, which includes Nasutitermes and Microcerotermes species that are consider the true higher termites and the most recently evolved species.
Drywood termites are very different to subterranean termites in that they do not need a source of water or to be in contact with soil – they are quite able to live off the moisture content of the wood providing the environment is humid enough. As such they are found mostly in tropical areas. Infestations consist of small independent populations throughout the structure. One of the key signs of their presences are their droppings – unusual hexagonal pellets.
In Australia there is the native drywood termite, Cryptotermes primus, and also the introduced pest, the West Indian drywood termite, Cryptotermes brevis. The West Indian drywood is considered the most destructive termite in the world as it can persist in very small pieces of wood, can easily spread between timbers and can be very hard to detect and control. It often causes significant damage before detection and can only be eradicated by fumigating the whole house.
Dampwoord termites are not normally considered serious economic pests as they only tend to damage old timber, in very damp areas, conditions which are unusual in most houses. They are more commonly found in decaying wood. Like drywood termites they don’t have a central colony and persist as small independent groups. They are quite noticeable as they have a fairly large soldier caste, approaching 10 mm in some species.
The evolution of termites is a much researched area. It is now well established that termites evolved from an ancient line of cockroaches. This makes the “white ant” name even more of a misnomer.
How they achieved this and how the different species developed appears to have been heavily influences by changes in their gut microbes.
Find out more about evolution of termites.
Climate change, particularly increasing temperatures and changes in rainfall, will impact both termite behaviour and the areas where they can survive. It is expected that the areas suitable for the damaging species will increase and therefore the level of damage experienced by a country will also increase.
Coupled with human assisted dispersal, which can introduce alien species into new geographies, the threat posed by termites is expected to increase.
Here are some examples of the potential spread of termites due to climate change.
Here are some examples of the potential spread of termites due to climate change.
More magazine article on the latest termite research.