Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Life cycles of insects

All insects start as eggs.

There are 2 different types of life cycle:

  • young stages (nymphs) look similar to adults. In a cicada, for example:
    • a nymph hatches out of the egg;
    • the nymph then feeds on the roots of plants underground, often for several years;
    • the nymph looks a bit like the adult cicada, but it is white and has no wings;
    • during this time as a nymph it sheds its skin several times and grows bigger and bigger;
    • eventually it crawls out of the ground and climbs up a tree where it sheds its skin for the last time;
    • it emerges from its nymphal skin as the adult cicada with its wings;
  • young stages (larvae) look different from the adults. In insects like butterflies, beetles, and flies:
    • the egg hatches into a caterpillar or larva;
    • the larva feeds for anything from days to several years (different insects have larvae feeding on many different types of food);
    • the larva looks very different from the adult insect;
    • when the larva sheds its skin for the last time it becomes a pupa;
    • the pupa is a resting stage; it is usually fixed in one place, often inside a cocoon made by the larva, and it can't move much;
    • inside the pupa the body of the larva breaks down into a kind of living soup, and reorganises itself into the adult insect;
    • these big changes in the life cycle of insects are called metamorphosis, which is a Greek word meaning "change of shape" or "transformation".