Order: Odanata - Dragonflies (Anisoptera); Damselflies (Zygoptera); and others
These Insects have an aquatic larval stage where it spends most of it's life. This water born phase is usually one to two years but up to 6 years before reaching the adult stage. There is no pupal stage, just a number of larval moults. The final moult brings wings.
For the adult stage, large compound eyes and slender abdomens are defining characteristics. Other traits are small antennae and 2 pairs of transparent veined wings. Most of their information processing is linked to the large eyes. They are both predators and prey, feeding on mostly small insects such as flies. Dragonflies do not actively search out prey during cooler temperatures but damselflies do. Predators such as birds, frogs, spiders, fish and lizards keep populations in check. Defences are their excellent flight agilities and visual response. Males are quite territorial.
Odonata species often occur near streams, ponds and rivers and marshy areas. Some species are sensitive to a more narrow ecological range such as vegetation, water acidity, water calmness and pollution. Others are adaptive to more varied habitat. Generally though, occurrence of dragonflies and damselflies indicate favourable ecosystem health.
Fossils of early now extinct ancestors date back to 325 million years. A 155 million year old fossil of Protoanisoptera wittei, found in Germany, had a wingspan of 15 cm. Another fossil specimen found in France, from the family Meganeuridae had a wingspan of 70 cm. Odonata fossils, not as large, have been found dating back 250 million years. Early odonates may not have had a larval stage.
