Infraorder Isoptera
Isoptera used to be an insect order on its own, but it was reclassified due to recent genetic evidence that strongly suggests that they evolve directly from true cockroaches. There are 2976 species of extant termites in the world; 258 described species (90 undescribed) are found in Australia. Termites are one of the few groups of insects that are eusocial; they have the highest level of organization of sociality. A division of labour and closed system of communication exists inside their colony, and is the reason why they are regarded as a ‘super-organism’. They are extremely successful insects and economically, they cause more than a billion dollars in damage to homes every year.
Appearance
Termites are white to brown in colour, have straight beaded antennae, a straight abdomen, and chewing mouthparts. Their reproductives have equal-sized wings. Their colonies comprise of different castes, each with a different function or role. The eggs hatch into nymphs, which then develop into the following castes after a few moults:
Primary reproductives. They are the sexual forms of a colony and may be kings and queens in the future. They develop inside the colony and after their last moulting stage, they emerge as fully winged reproductives or alates. They have compound eyes and are darker in colour than any castes, and are larger in size. They also have thicker cuticles which enable them to resist water loss when they leave the parent colony to make their own.
Supplementary reproductives (neonetics). They are new queens that are selected from the colony when the queen’s reproductive capacity declines or is she dies. Supplementary queens are selected from reproductives developing in the colony; they will never leave the colony to undergo a colonizing or nuptial flight.
Workers. They forage, store food, feed the king and queen and all the other castes, take care of the young, and maintain the tubes and nests of the colony. They are sterile, blind, very pale, and have thin cuticles that are prone to desiccation when they leave their colony.
Soldiers. They have distinctively shaped and darker heads, and are typically bigger than workers. Soldiers function as the protectors of the colony against invaders, particularly ants.
Biology and Behaviour
Most termites primarily live in dark, moist underground nests and tunnels or within sound and decaying wood. They seldom venture into drier environments but, when necessary, construct mud tunnels for protection. Nest types vary from simple hollowed-out sections in decaying logs to more sophisticated structures underground, as mounds, or on trees. Termites can adeptly control temperature and humidity within their nests.
Termites rely on cellulose-rich plant materials for their main food source, obtained from sources like wood, grass, paper, and leaf litter. They also recycle nutrients by breaking down cellulose, making them essential for contributors to natural ecosystems.
Preproduction involves a yearly colonizing flight of fully developed alates, occurring in suitable weather conditions. Future kings and queens disperse, undergo courtship upon landing, and if successful, build a nest. This slow process mate take a few years for the colony to become populous. Some species utilize “budding-off”, producing supplementary reproductives that break away from the parent colony without flying.
Pest Status
Termites play a significant economic role as a group of insects. They inflict considerable damage to structures that include wood, poles, posts, fences, bridges, forest trees, and various crops in dry inland regions. In urban areas, even well-established ones, termites, especially subterranean termites, persist in causing damage to buildings and fences. Surprisingly, they can even harm the limited timber elements in the upper levels of structures that are primarily constructed with concrete and glass.