What is the term for the development process of insects that includes stages from egg to larva to pupa to adult?

The term describing the development process of insects that progresses through the stages of egg, larva, pupa, and adult is metamorphosis. This term specifically refers to the transformation that insects undergo as they develop from one life stage to another, particularly in complete metamorphosis, which includes a distinct transformation where the organism takes on a completely different form at the adult stage compared to the larval stage.

Metamorphosis plays a crucial role in the life cycle of many insects, allowing them to adapt to different ecological niches at various life stages. The larval stage, for instance, is often focused on feeding and growth, while the adult stage is typically oriented towards reproduction.

This definition clearly distinguishes metamorphosis from the other terms. Eclosion refers to the process of an insect emerging from its egg or pupa. Diapause is a period of suspended development that some insects enter to survive unfavorable environmental conditions, and instar refers to the developmental stage between molts in the life of an insect, particularly in the larval stage, without the complete transformation that defines metamorphosis. Thus, the correct answer aligns with the holistic development and various life stages of insects.