Insect Life Cycles

Most adult female insects are oviparous, meaning they lay eggs which hatch after deposition

Some adult female insects are viviparous, they lay larvae or nymphs, and the eggs rupture in female reproductive tract

Simple Metamorphosis

Hemimetabolous; nymphs emerge from the eggs which resemble the adult but are sexually immature. The nymph grows and undergoes several ecdyses, also known as moults. The nymphs becomes adults.

Hemimetabolous = Egg - Nymph - Adult (3 stages).

Complex Metamorphosis

Holometabolous; larva emerge from the eggs and do not resemble the adults. The larva feed, grow and undergoes several ecdyses. Larvae undergoes a quiescent stage where the outer cuticle hardens to form a pupa, some species have a silken cocoon. The adult develops inside the pupal case before emerging e.g. Fleas and dipteran flies

Holometabolous = Egg - Larva - Pupa - Adult (4 stages).