Dragonfly Incomplete Metamorphosis

Many people are unaware of the fact that dragonflies spend the majority of their life underwater. Like butterflies, dragonflies and damselflies have multiple stages of development, but instead of four stages like butterflies they only have three stages of development or what is called an incomplete metamorphosis. Unlike butterflies dragonflies do not go through a pupal state, instead they go directly from their larval state, called a nymph, to their adult stage which is a dragonfly.

Dragonflies typically live from one to three years in their larval form, although some species live longer and others less. The nymphs hatch from the eggs which are deposited into the water by the female. The nymphs are carnivorous eating aquatic insects, other nymphs, tadpole and small fish. They frequently molt as their size increases. When they are ready to become adults they go into a type of rest state called diapause,where the final necessary changes in their form are made. When the diapause is complete the nymph will crawl out of the water, typically onto to a rock or hanging vertically from vegetation on the shoreline. Then a split occurs in the skin at the back of the head. The split continues down the back making enough room for the new dragonfly to emerge. The picture above are the skin husk that remains after the dragonfly emerges. These appear to be the husk of emergent clubtails which were photographed on the shore of the St Croix River.