
Termite Biology
We’ve spent a lot of time talking about how to eradicate termites from your home, but not a lot of time explaining what drives these little creatures to attack and how it’s even possible for them to eat away your greatest asset.
Here’s some information from the Victorian Department of Human Services that we thought you might find interesting!
“Termites”, Department of Human Services
Termites belong to the insect order Isoptera, meaning ‘equal wings’. Winged termites have four wings equal in size and shape. Termites are often wrongly referred to as white ants; however, as they are neither white, nor ants, this term should not be used. Termites are in fact, closely related to cockroaches. The digestive system of termites contains a variety of micro-organisms which assist in the digestion of the plant fibre cellulose. Over 350 species of termites are found in Australia, of which only approximately 20 commonly cause damage to buildings, 5 in Victoria alone. Although termites are generally considered to be destructive timber pests, they play important ecological roles, providing nest holes for lizards, birds and possums, assisting in the breakdown of organic matter, returning nutrients to soil, and assisting with soil aeration.
CASTES
Termites are social insects, living and working together within nests or colonies of various sizes. Termites take several different forms. Each form, or caste, has different functions to perform within the colony. They communicate by smell and touch.
ALATES
Alates, meaning ‘winged ones’, are the true adult termites. They have eyes, wings, darker colouring and are fertile. Their wings are twice the length of their body and are shed after he colonising flight is made. Shed wings are a good indication of termite presence.
REPRODUCTIVES
The reproductives live in a central chamber in the nest where the female, or “Queen”, will lay many thousands of eggs each year over her life span of approximately 10 years. The male, or “King”, is responsible for fertilising the Queen. The reproductives exist as one of two possible forms. The macropterous King and Queen made the colonising flight as alates and established a new colony after they shed their wings. A macropterous reproductive can therefore be identified by the presence of retained wing bases (little triangular stubs on the thorax).
The supplementary reproductives occur as a result of the death or deterioration of the macropterous reproductives. Supplementaries arise from among the younger, wingless reproductives developing within the colony, therefore lack any evidence of wing bases.
COLONISING FLIGHT
HABITAT
The conditions maintained within a termite colony are such that the termites are not normally at risk of moisture loss as a result of the exposure of their soft, thin cuticle to a harsh dry external environment. The temperature within the nursery of a large nest ranges between 10` C and 35` C but rarely varies more than one degree a day. The relative humidity is approximately 100%. The moisture required to maintain the temperature and humidity is obtained from the soil, leaking plumbing or decaying timber.
LIFECYCLE
The lifecycle of a termite consists of four stages of development with young termites developing into four different castes. The temperature, food quality, and activity of the colony affects the interval over which termites develop from egg to adult. Termites develop by moulting or shedding their outer cuticle once a growth period ceases. The Queen adds a new set of ovaries at each moult so that her abdomen eventually becomes quite large, a condition referred to as physogastry. Shortages of a particular caste create a hormonal imbalance within the colony. This is then corrected by the development of more young termites into that caste.
It is important to correctly identify the type of pest termite before beginning treatment as the location of the nest and other habits of the colony will indicate the most appropriate method. As the soldiers of each colony possess such prominent features the termite species is most easily identified by examination of an individual of this caste.
SCHEDORHINOTERMES
HETEROTERMES FEROX
Heterotermes are widely distributed throughout Australia, however, they are not considered to be a major pest species except in the Northern Territory. The small colonies attack fence posts, timber flooring, and paling fences within a small radius of the nest.
Heterotermes ferox specialize in feeding on small timbers on the soil surface and as a result are very commonly found. The soldiers of this species are up to 4.75mm in length with long, dark jaws and distinctly long parallel-sided heads.