Metamorphosis is a biological process whereby an animal changes from an immature form to an adult form. It involves going through distinct physiological stages, and is seen in some fish, amphibians (frogs, toads, salamanders) and insects. The term metamorphosis is derived from the Greek words meta “transforming” and morphe “form.” Metamorphosis may be complete or incomplete.
Incomplete metamorphosis in insects involves three stages – egg, nymph, adult. The immature stages (nymphs) look like miniature adults. Examples are grasshoppers, cockroaches and the true bugs (cicadas, aphids, stink bugs, and others). Katydids, grasshoppers and crickets belong in the same family.
During complete insect metamorphosis, there are four stages – egg, larva, pupa, adult. Larval stages are called caterpillars, grubs and maggots. Caterpillars are the larvae of butterflies and moths, grubs the larvae of beetles and maggots the larvae of flies.
Pupae of the various insect groups have different names. For example, a chrysalis is the pupa of a butterfly, cocoon of a moth, tumbler of a mosquito and so on. There are many kinds of pupae, each with a different name.
For insects with incomplete metamorphosis, all three stages are seen during the winter. Most of what we see during the winter for insects with complete metamorphosis are eggs and pupae. There may be some larvae and adults in leaf litter.
