From the Greek words meta: " after " and morphos: " form ". The adult form is very different from that of the caterpillar. Complete: that which has four stages.
In insects that undergo incomplete metamorphosis, there are only three stages: egg, larva or juvenile and adult: the larvae look like adults and can have the same diet as adults, such as the Orthopterans (grasshoppers). (In Europe, the woolly aphid Eriosoma lanigerum, has no egg stage, females are viviparous and do not lay eggs but produce juveniles, and are, moreover, parthenogenetic).
The butterfly is an insect that undergoes complete metamorphosis. © Bernard Schmeltz