Termites: Isoptera

Termites are the most primitive group of living winged insects that lay their eggs on land. Some scientific studies suggest that termites are most closely related to cockroaches. The most primitive cockroaches, wingless wood cockroaches from North America, closely resemble termites in their appearance and behavior. Similarly, the most primitive termites, Mastotermes darwiniensis from Queensland, Australia, look and act like cockroaches. The similarities between termites and cockroaches suggest that termites could be called "social cockroaches" and cockroaches could be called "solitary termites." However, there are major differences in overall body plan and wing structure. Still, it is very likely that termites and cockroaches had a common ancestor but then branched off into their own distinct groups a very long time ago.

Termites have a caste system, meaning that each member of a group has a different function within the group. Each "caste" is told apart from another by its size, form, and the ability or lack of ability to reproduce. The castes usually consist of workers, soldiers, and kings and queens. Only the kings and queens reproduce. Termite workers and soldiers are unable to reproduce. Termites are usually pale and soft-bodied. Their thorax, or midsection, is broadly attached to the abdomen, giving them a thick waist. They have short antennae (an-TEH-nee) with beadlike segments. The workers and soldiers might be either male or female. Worker termites have powerful jaws for chewing wood or other plant materials. Depending on the species, soldiers may have big heads with sharp, scissorlike jaws or smaller, pointed heads. They tend to be larger and darker and have heavier bodies than the workers.

Only the insects that reproduce have wings, mate, and lay eggs. The forewings and hind wings of these termites are the same size. Termites hold their wings flat over the body when resting. The wings of king and queen termites break off just before the point where they are attached to the thorax. Queens among the mound-building termites often have bloated, sausage-shaped abdomens and are basically egg-laying machines. They range in length from 2 to 4 inches (5.1 to 10.2 centimeters). Larvae (LAR-vee), or young termites, look like the adults.