A complete (complex) life cycle of an insect includes which of the following sets of life stages?

• A. Egg, Larva, Pupa, Adult
• B. Egg, Nymph, Adult
• C. Larva, Pupa, Adult
• D. Egg, Nymph, Pupa, Adult

Answer: (A)

Complete metamorphosis in insects involves four distinct life stages: egg, larva, pupa, and adult. The larva and adult look and behave very differently, and a transformative pupal stage occurs between them, allowing the insect to switch from a feeding, growth-focused juvenile to a reproductive adult. This four-stage sequence is what defines a complete life cycle.

Insects that do not undergo complete metamorphosis go through an egg, nymph, and adult series, where the juvenile form (the nymph) usually resembles a miniature adult and there is no pupal stage. So a life cycle described as egg–nymph–adult would not be a complete metamorphosis. The correct set, containing both larva and pupa and totaling four stages, reflects complete metamorphosis.