What is defined as a complete metamorphosis?

A complete metamorphosis is characterized by a life cycle that consists of four distinct stages: egg, larva, pupa, and adult. This process is commonly observed in insects such as butterflies, beetles, and bees.

During the egg stage, the organism begins its life as a fertilized egg. Upon hatching, it enters the larval stage, where it often looks vastly different from the adult form; for instance, a caterpillar looks very different from the butterfly it will eventually become. The larva often focuses on growth and feeding, increasing in size dramatically.

After sufficient growth, the larva transitions into the pupal stage, where it undergoes significant internal transformation. This stage is crucial, as many of the larva's structures are reorganized to form the adult characteristics. Finally, in the adult stage, the organism emerges from the pupa, having completed the transformation into a form that is typically capable of reproduction.

This sequence emphasizes the complexity and dramatic changes that organisms undergoing complete metamorphosis experience, distinguishing it from incomplete metamorphosis, which typically involves only three stages (egg, nymph, adult) and lacks a distinct pupal phase.