Insect Life Cycles

Approximately 5% of insects spend all or part of their life cycle in water. The immature stages of these aquatic insects often have streamlined bodies and they breathe with gills.

There are two types of insect life cycles. Complete metamorphosis includes a larvae and pupaes stage. Incomplete metamorphosis includes only a nymph stage.

Nymphs

Nymphs are a feeding stage that look like a small copy of the adult but with wingpads and not wings. Nymphs gradually grow larger by shedding their hard, confining exoskeleton. The last moult is done at the water's surface or out on rocks and plants as their new wings unfold.

Larvae
Larvae are a feeding stage that looks like fat grubs or caterpillars. Larvae appear very different from their final winged adult stage. These "ugly ducklings" pupate before changing into beautiful flying adults.

Pupae

Pupae are a non-feeding stage much like a moth cocoon or a butterfly chrysalis. During pupation, aquatic larvae "hide-out" and transform into an adult stage with wings. A case or mummy-like covering may protect the pupae.