What stage is not present in incomplete metamorphosis?

Insects that undergo incomplete metamorphosis do not have a pupal stage. Instead, they transition from an egg to a nymph and then to an adult. The nymph stage resembles a miniature adult and can go through several molts before reaching maturity, which is characteristic of this type of metamorphosis. Incomplete metamorphosis allows for the young to be more or less similar in appearance to the adult form throughout their development, differing chiefly by size and maturity rather than form.

In contrast, complete metamorphosis involves four distinct life stages: egg, larva, pupa, and adult. Since the question specifically asks which stage is absent in incomplete metamorphosis, the correct answer highlights that the pupal stage—which is a crucial component of complete metamorphosis—is not part of the lifecycle of insects that undergo incomplete metamorphosis.