Odonata: An Ancient Order of Insect

Apart from being beautiful creatures with prehistoric ancestry, dragonflies and damselflies are highly useful biological indicators of our ecosystem.

- Amar Kumar Nayak

The order Odonata (Pneoroptera) represents two sub-orders Anisoptera (Dragonflies) & Zygoptera (Damselflies) and a link order Anisozygoptera, which represents only two species, among them one living fossil is found in the hilly areas of Darjeeling. Odonates are one of the dominating aquatic (larval stage) & terrestrial (mature stage) insects, flying over ponds, streams, rivers, forest and meadows, spending maximum time of their life around water bodies – the best place to observe them. Dragonflies are known as flying machines due to their extensive flying capabilities. These fliers can even fly backwards, move vertically like a helicopter or stop in turn in the midst of a rapid progression.

In general, dragonflies and damselflies are collectively known as Odonates. The differences between them are based on these basic morphological characters: (1) Dragonflies are strong fliers, fly fast and high but damselflies are comparatively weak fliers, fly over the ground or water. (2) In Dragonflies the fore wings and hind wings are unequal in size and the hind wings are broader at the base but in damselflies the fore wings and hind wings are approximately of same size and shape. (3) While perching, Dragonflies keep their wings open and spread out on both the sides of thorax while in damselflies they are held closed together and folded over the abdomen. (4) Dragonflies have a stouter abdomen whereas Damselflies have slim abdomens. Sometimes dragonflies and damselflies are confused with owlflies, mayflies & antlions but Odonates can be easily distinguished from these three flies for the presence of their antennae.