Sri Lanka has a rich dragonfly fauna. There are many species that are common to much of Asia and a number of endemics. Dragonflies can be found for most of the year, though many species have specific flight times. There are 117 species of dragonflies and damselflies which 53 are found endemic. Dragonflies are in fact three suborders with two suborders present in Sri Lanka. Suborder Anisoptera are dragonflies. Suborder Zygopteraare damselflies. Both are belonging to Odonata.
A dragonfly has a life span of more than a year, but very little of that life is actually as an adult dragonfly. There are three stages of the dragonfly life cycle, the egg, the nymph, and the adult dragonfly. Most of the life cycle of a dragonfly is lived out in the nymph stage and you donít see them at all, unless you are swimming underwater in a lake or pond with your eyes opened, of course.
A male and a female dragonfly will mate while they are flying in the air. After two dragonflies mate, the female dragonfly will lay her eggs on a plant in the water, or if she canít find a suitable plant she will just drop them into the water.
Once the dragonfly eggs hatch, the life cycle of a dragonfly larva begins as a nymph. A nymph looks like a little alien creature. It hasnít grown its wings yet and has what looks like a crusty hump hanging onto its back. Dragonfly nymphs live in the water while they grow and develop into dragonflies. This portion of the dragonfly life cycle can take up to four years to complete, and if the nymph cycle is completed in the beginning of the wintertime, it will remain in the water until spring when it is warm enough to come out.
Dragonfly nymphs live in ponds or marshy areas because the waters are calmer than in a stream or river. Sometimes they can be found in the calmer backwaters of rivers, too. Dragonfly nymphs may eat smaller dragonfly nymphs as they develop.
Once the nymph is fully grown, and the weather is right, it will complete the metamorphosis into a dragonfly by crawling out of the water up the stem of a plant. The nymph will shed its skin onto the stem of the plant and will then be a young dragonfly. The skin that the nymph left behind is called the exuvia and you can find the exuvia still stuck to the stem for a long time after the dragonfly has left it.
Once the dragonfly leaves the exuvia it is a full grown dragonfly. The dragonfly will hunt for food and begin to look for a mate. Once the dragonfly finds a mate, the female will find a body of calm water that will be a good place to lay her eggs, and the life cycle of the dragonfly begins all over again. Adult dragonflies only live about two months.