insect

insect Any of more than a million species of small, invertebrate animals of the class Insecta, including the beetle, bug, butterfly, ant and bee. There are more species of insects than all other species combined. Adult insects have three pairs of jointed legs, usually two pairs of wings, and a segmented body with a horny outer covering or exoskeleton. The head has three pairs of mouthparts, a pair of compound eyes, three pairs of simple eyes, and a pair of antennae. Most insects can detect a wide range of sounds through ultra-sensitive hairs on various parts of their bodies. Some can ‘sing’ or make sounds by rubbing together parts of their bodies. Most insects are plant-eaters, many being serious farm and garden pests. Some prey on small animals, especially other insects, and a few are scavengers. There are two main kinds of mouthparts – chewing and sucking. Reproduction is usually sexual. Most insects go through four distinct life stages, in which complete metamorphosis is said to take place. The stages are ovum (egg), larva (caterpillar or grub), pupa (chrysalis), and adult (imago). Young grasshoppers and some other insects, called nymphs, resemble wingless miniatures of their parents. The nymphs develop during a series of moults (incomplete metamorphosis). Silverfish and a few other primitive, wingless insects do not undergo metamorphosis. Phylum Arthropoda See also arthropod