Webspinner is any of a group of small, slender insects that spin nests of narrow, interconnected silk tunnels. Webspinners typically inhabit warm or tropical climates. They often build their nests under bark, leaves, or stones. Webspinner nests may extend deep into the soil.
Adult webspinners can grow from 1/6 to 4/5 inch (4 to 20 millimeters) long. They have distinctive enlarged tarsal segments at the ends of their front legs. These segments somewhat resemble boxing gloves, and they contain special glands for producing the silk used in nest construction. Webspinners are the only insects that spin silk with their front legs. Adult male webspinners typically have two pairs of thin, flexible wings. They can pump blood into the wing veins to stiffen them during flight. All female webspinners and some males lack wings.
Webspinners live in small colonies (groups) that usually contain one or more adult females and their developing offspring. As the colonies grow, the webspinners expand the tunnel system to create new living space and to reach new sources of food. The insects use their chewing mouthparts to eat such food as moss, bark, dead grass and leaves, and plantlike organisms called lichens.
Webspinner tunnels are so narrow that the insects cannot turn around in them. However, well-developed muscles in their hind legs enable webspinners to run backward as easily as they run forward. Several sense organs guide their rapid movements, including antennae; compound eyes, which consist of many tiny lenses; and cerci, a pair of short feelers on the back of the abdomen. Males can even fold their wings over their head when running backward.
Male webspinners travel from their original colony to another before mating, and they die soon after they mate. Sometimes, the female eats her male partner. All webspinners gradually pass through three stages of development—the egg stage, the nymph stage, and the adult stage.
