In the tropical and subtropical regions of the world, live the members of a little known order of insects, the Embioptera or web-spinners. It is a small order with only about 300 species in 13 families described, but because they are small and cryptic, many more species may remain to be discovered. Embids are small, being only 4 to 15 mm long. Their bodies are soft, elongated and usually dull brown, grey, black or white in colouration. They have chewing mouthparts and short filiform antennae. Males usually have wings but the females are wingless. The name Embioptera comes from the Greek and means “lively wings” which refers to the characteristic fluttering of the male’s wings.
Their chief characteristic is that they spin webs of silk which they shape into tunnels and then live in groups within these protective tunnels. Each tunnel is inhabited by a single female and her young. The silk is produced by glands on the tarsi of the front pair of legs. The tunnels protect the embids from predators and also from desiccation, as they are soft-bodied and so prone to drying out. Even the very young can spin silk.
Their sex life is short and not that sweet. The males are born with large jaws but they never feed. Instead, when they mature, they make a short dispersal flight from their home colony, find a new colony, land, mate and die. The females add insult to injury by eating the males, but that recycles the male bodies into eggs so at least it’s not wasteful. The female tends her eggs and even feeds the young when they hatch with chewed plant materials.
Embids have an incomplete life cycle. Eggs develop into nymphs that are simply small versions of the adults. Embids eat dead plant materials, such as grass, leave, moss, lichens and bark. They play dead when disturbed but can also run quickly. They can run backwards as easily as forwards. They are nocturnal, staying in their tunnels during the day and coming out at night to hunt for food.
They are relatively common but seldom seen. Disturbing leaf litter will reveal their webbed tunnels but most people mistake them for spider webs and never see the insects within. They are not pests and so have no economic importance.
References: O’Toole, C. 1986. The Encyclopedia of Insects. George Allen and Unwin
Borror and DeLong, 1971. An Introduction to the Study of Insects. Holt, Rinehart & Winston
http://www.earthlife.net/insects/embiop.html http://www.ento.csiro.au/education/insects/embioptera.html
