Order Isoptera - Termites or White Ants

• Yellow-necked Termite

Social insects living in large communities, with several different forms or castes, viz, reproductives ('kings' and 'queens'), soldiers and workers. All are soft-bodied and generally pale in colour, with biting mouthparts. The soldiers have a large head - in some species with large, powerful jaws - in others with a pointed rostrum from which a poisonous, repellent liquid can be ejected. The reproductive castes have two pairs of similar long, narrow wings (see below), but these are soon shed once they start nesting. Other castes are wingless. The wingless forms have rudimentary eyes or none at all. Abdominal cerci always very short. Metamorphosis simple. All castes are long-lived. A king and queen may live together in their colony for many years - up to 50 years has been quoted for some species - and individual soldiers and workers may live up to four or five years. Termites are mainly tropical insects, with over 2,000 species worldwide. Only two species are native to Europe, both more or less confined to southern regions.

At certain seasons, termite colonies produce winged reproductive castes (as shown opposite). These new kings and queens have a brief flight, which may be sufficient to carry them a short distance away from their parent nest, and then they come down to earth and break off their wings. When opposite sexes meet they search out a suitable nest site and excavate a small nuptial chamber to start a new colony.

Photo: V.J. Stanek ©

Termite nests vary a great deal in construction. The more primitive groups simply excavate galleries in dead wood or make underground nests. The more advanced termites build huge mounds, largely from soil excavated from their underground chambers and cemented with saliva. These large nests, or termitaria, are especially common in Africa and Australia.

The Australian Compass Termites, Amitermes meridionalis, nearly always build their large, slabe-like nest columns with the narrow ends pointing north-south. This probably helps prevent them from becoming overheated during the middle of the day.

Photo: Australian Information Bureau ©

Some termites eat grass and fungi, but most feed on wood and can be very destructive to the timbers of buildings and other wooden structures. Wood is not an easily digested material, and termites rely on various micro-organisms (protozoa or bacteria) in their gut to break down the tough cellulose of wood. Some members of the colony get their food after it has been partly digested by the workers. The reproductive castes and soldiers are always fed in this way, and so are some of the young stages. Food may be regurgitated by the workers, or else they pass partly-digested faecal pellets which are consumed by the other termites. The workers of some termites cultivate fungi in special 'fungus gardens' contained in chambers scattered through the nest. The fungus is grown on shredded and chewed vegetable matter and then harvested as food for the colony.

Description. Pale yellow-brown, with the reproductive castes darker in colour than the workers and soldiers. King (a) about 10 mm long; queen (b) about 15 mm long, with the abdomen greatly distended and swollen with eggs; workers (c) up to 7 mm long, with normal head and jaws; soldiers (d) about 10 mm long, with a long cylindrical head bearing large jaws. The king and queen are illustrated as they would appear in an established colony, after shedding their wings.

Biology. This is a dry-wood termite, living in dead trees and logs. Occasionally found in building timbers. It forms relatively small colonies consisting of a royal pair and a few hundred working young and soldiers.

Distribution. Parts of southern Europe around the Mediterranean coasts, from Portugal to Greece and on to the Middle East.

Illustration: adapted from Chinnery 1993