What term refers to the developmental stage where significant changes occur in insects with complete metamorphosis?

The term that refers to the developmental stage where significant changes occur in insects with complete metamorphosis is "Pupa." This stage is crucial as it is when the insect undergoes dramatic transformations internally and externally, transitioning from a larval form to an adult form. During the pupal stage, the insect is generally inactive and encased in a protective shell, allowing for the reorganization of its body structure.

Insects such as butterflies and beetles exemplify this complete metamorphosis, moving from egg to larva (larvae), then to pupa, and finally to adult. Understanding this developmental process is essential in pest management because it highlights the life cycle stages that may require different control strategies depending on the timing of treatments. The other stages—egg, larva, and adult—do not capture the pivotal transformation that occurs specifically during the pupal stage.