TERMITES - Biology
and Behavior of Termites
ABOUT TERMITES - their description, ecology, biology and behavior
TERMITES commonly called WHITE ANTS are not related to ANTS
The differences distinguishing both Insects are Worker Termites are coloured white to cream to pale brown Worker Ants vary in colours of brown and black Worker Termite has no distinct constriction ( WAIST ) between thorax ( chest ) and abdomen ( stomach )
Worker Ant has a distinct constriction ( WAIST ) between thorax and abdomen
Worker Termite has NO eyes and has beadlike antennae
Worker Ant has compound eyes present and has elbowed antennae
TERMITES are a very successful group of Insects who date back more than 100 million years. In Australia there are over 300 species represented by the FAMILIES - Mastotermitidae, Termopsidae, Kalotermitidae, Rhinotermitidae and Termitidae.
TERMITES can be grouped into three ( 3 ) categories
DAMPWOOD Located in trees, stumps, logs and areas of timber in contact with moist soil. Generally most are strictly pests of trees and are not considered significant pests of buildings. They may sometimes damage decaying and weathered timber and timbers in wet building subfloor areas with poor ventilation and drainage. Their damage in forests degrades logs for milling into building timbers. They generally depend on the moisture in the tree and have galleries in the softer growth rings. They usually do not form a large central colony but live in many small colonies in the wood.
DRYWOOD Exist in dry wood in areas where atmospheric moisture is usually
HIGH, generally coastal sub-tropical and tropical areas. They obtain moisture from the wood they live in and have no contact with the ground. Native species live in dead branches, branch stubs, fire scars. Attack mainly sapwood but can enter into heartwood. Their presence indicated by dry sand-like faecal pellets called ‘frass' which is expelled from openings in the gallery system. The introduced species Cryptotermes brevis - the West Indian Drywood Termite, is considered the World's most destructive Drywood Termite. It has been found in Sydney. Attacks wood in buildings, including furniture.
SUBTERRANEAN are the main pest species that damage buildings and structures in Sydney. They usually nest in cavities in trees, stumps left in the ground, inaccessible subfloor areas containing moisture and decaying wood, behind retaining walls etc. Worker Termites tunnel through soil from the nest in search of food. They make galleries inside wood and earthen shelter tubes over obstacles to reach food. Their concealed gallery systems are sealed to maintain high humidity and even temperature, essential for their survival. Their presence and damage caused to buildings and structures often goes undetected for a long time.
LIFE CYCLE
Termites have a gradual metamorphosis with the larvae hatching from an egg into a similar form to the adult. It undergo's a number of MOULTS where it sheds the bodies outer covering called the exo-skeleton, allowing the body to grow, shortly after the new exo-skeleton hardens. This process continues through the NYMPH stage until it becomes a mature WORKER, SOLDIER or FULLY WINGED REPRODUCTIVE.
THE TERMITE COLONY
Termites are social insects meaning they live together in groups, called COLONIES .
The main pest species that damage buildings can have colonies numbering one ( 1 ) to two ( 2 ) million individual Termites.
A mature Colony of subterranean Termites has three principal CASTE members and immature forms which are generally called nymphs.
Each CASTE members have different specific tasks to perform.
WORKERS
Are usually the greatest number of individuals in a colony. They are males and females whose sexual characteristics have not developed.
Workers of the pest species damaging buildings are wingless, sterile and blind. Mostly translucent white to cream and often coloured by the food they eat which can be seen in the gut tissue through their thin cuticles, ( outer covering or exo-skeleton).
They do the work of the colony. Building and repairing the nest and galleries through which they travel, gather the food for the colony, feed the other caste members, tend to the Queen (s) and King (s), the eggs and the young.
SOLDIERS
Are distinguished from other castes by their heads which are heavily armoured and pigmented. The soldiers of the pest species damaging buildings are wingless, sterile and blind. They are males and females whose sexual characteristics have not developed.
Soldiers occur in two types. Mandibulate with well developed jaws and Nasute whose head has been drawn out into a snout with tiny mouth underneath. Both have been modified for their role in defending the Termite colony. Some species have glands that discharge secretions at their enemies. Soldiers have to be fed by the Workers.
Soldiers are the easiest way to identify the species of Termite.
REPRODUCTIVES - Are the sexual forms in a colony
PRIMARY QUEEN & KING
Are the original winged reproductives called ALATES that left the parent colony in a colonising flight, dropped to the ground, shed their wings, mated and found a suitable nesting site to form a new colony. Both reproductives can live for 20 to 30 years or more. Queens in some species can lay 1,000 to 2,000 eggs per day.
As the Queen and King age and egg laying declines some species can select developing reproductive ALATES to assist the original Queen and King with reproduction. If necessary they can replace them in the colony. They will never go on a colonising flight and are called SUPPLEMENTARY QUEENS AND KINGS.
ALATE REPRODUCTIVES
Are the future Queens and Kings developing within the colony prior to the colonising flight.
When conditions are right in the warmer months of the year, around November and December, the outside conditions are hot and humid, ideally before or after a storm, near dusk, the fully winged ALATES will fly out in THOUSANDS on the colonising flight. Often everywhere you look the sky is massed with small flying insects. This happens every year in Sydney.
ALATES are not strong flyers and so their dispersal is confined to the area surrounding the nest. They could travel greater distances if winds were blowing to assist dispersal. They are attracted to lights and can enter buildings.
If conditions of shelter, moisture and decaying wood were present a nest could be established inside the building without ground contact.
Decaying stumps in the ground, timber retaining walls, entry into filled areas under patios, steps, laundries, bathrooms etc where there is moisture and decaying wood off-cuts left by the builder. These are some of the places suitable for a Termite colony to establish.
It may take 3 to 5 years before that colony has sufficient numbers to seriously damage timber in a building or structure.
IMPORTANT INFORMATION
Some pest species of Termites damaging buildings can establish new colonies without going on a colonising flight.
REPRODUCTIVES , WORKERS and SOLDIERS split off from the main Colony and establish themselves close by.
COLONY NESTS
Are often characteristic of the Termite species and will aid with its identification.
Inside the trunk, branches and in the root crown area of living trees.
In dead and decaying trees and stumps in the ground, behind timber retaining walls, in filled areas under patios, steps, laundries, bathrooms etc where there is moisture and decaying wood off-cuts left by the builder.
They can be earthen mound nests of varying sizes and shapes.
Arboreal nests on the outside of trees.
Small colonies in dry wood, trunks and branches of trees.
Amongst wood mulch in garden areas.
FEEDING HABITS
The basic food requirement of Termites is CELLULOSE which it gets from wood and plant materials.
CELLULOSE provides the Termite with its carbohydrate energy source.
PROTEIN also essential in a Termite's diet is supplied to them by FUNGI that decay wood and plant material.
The WORKER TERMITE CONSUMES the FOOD where they FIND IT.
They feed all the other CASTE members of the Colony.
Termites FEED on WOOD and WOOD PRODUCTS . eg Framing timbers and linings, gyprock, flooring, skirting boards, door and window frames etc in buildings. Furnishings, cupboards, wardrobes, bed-heads and frames, shelving and anything manufactured from WOOD e.g. paper and cardboard, books, business records, magazines, cardboard boxes etc.
Some PLASTICS contain cellulose and can be DAMAGED by Termites.
Termites damage and short out ELECTRICAL WIRING & FITTINGS requiring the services of an Electrical Contractor to repair. This is sometimes the way in which a Termite problem is first found.
Starting of fires in buildings have been attributed to this activity.
TREES and SHRUBS , dead fallen branches, leaves, bark etc, SURFACE VEGETATION and GRASSES .
If the above FOOD SOURCES are breaking down because of FUNGAL DECAY they will be more attractive to Termites.
NOTE : Some Termites only attack wood that is decaying. Many Termites are grass feeders.
BENEFITS OF TERMITES
The Termites role in the natural environment is the RECYCLING of dead plant material as NUTRIENTS to the SOIL
Another important aspect of their food gathering activities is TUNNELLING through soil. This allows AERATION and WATER PERCOLATION into the soil, with the recycling of nutrients the soils are improved. This can help in reducing water run-off which will aid in minimising SOIL EROSION.
DIGESTION OF FOOD
The cellulose of wood is digested in the hind-gut of Worker Termites by either Protozoan or Bacterial fauna, depending on the species.
They are essential in the conversion of cellulose into products that can be used by Termites as a carbohydrate energy source.
The WORKER TERMITES return to the COLONY NEST and feeds the other CASTE MEMBERS, they EXUDE FOOD from their ANAL and ORAL AREAS which the other Termites eat.
It is this feeding method of the Colony by the Worker Termites plus the habit of grooming (cleaning) one another that can cause the ELIMINATION of the COLONY.
By transmitting a Control Agent such as Chlorfluazuron, a Chitin Synthesis Inhibitor in bait, or treating of galleries and live Termites with Arsenic dust or Triflumuron dust, another Chitin Synthesis Inhibitor, the Control Agent can be ingested or adhere to the Termites moist bodies and passed throughout the Colony by the Worker Termites during the feeding process and grooming.
If enough Termites have been affected in this way the Colony can be ELIMINATED.
