The colourful life of dragonflies

These remarkable insects date back to dinosaur times, they eat mosquitoes and midges, and have a short, but vibrant lifespan
Chris Packham
guardian.co.uk, Saturday 25 July 2009 00.08 BST
On a warm summer's day a ramble along a riverbank or around a pond is likely to reward you with a dazzling display of brightly coloured dragonflies hawking along the waterway in search of prey.
These beautiful predators belong to the order known as Odonata meaning "toothed jaw" and look almost identical to large insects which flew over our forests at the time of the dinosaurs. With wingspans of up to 75cm those "monsters" must have been amazing.
Although known collectively as dragonflies there are two distinct groups, dragonflies and damselflies. The damsels are small delicate insects with four wings the same size and shape which are folded parallel to their body at rest. Their eyes are always separated on either side of the head. Dragonflies are usually larger, stronger flying insects that can often be found further away from water. Their hind wings are generally shorter and broader than their forewings, while massive eyes occupy most of their head. These wings are held open and flat across the back when the dragons are resting.
The brightly coloured adults represent the final and shortest part of the dragonflies' remarkable lifecycle, the vast majority of which is spent underwater. Once mated, a female dragonfly uses her long abdomen to dip her fertilised eggs below the surface of the water or inserts them into underwater vegetation. These develop into larvae from which flying adults emerge after anything from a few months to several years, dependent on species. This stage of their lifespan is relatively short with small damselflies living for just a couple of weeks and larger dragonflies unlikely to survive longer than a couple of months. Many become prey for birds, and large numbers starve, as in poor weather conditions neither they nor their potential prey can fly. Dragonflies are voracious carnivores eating up to 20% of their bodyweight daily. Their diet consists mainly of flying insects, particularly flies, midges and mosquitoes, whilst larger species may even tackle butterflies and moths.
Dragonflies have unique powers of flight and can hover or fly in all directions, covering up to 10 metres in a second. They can see all round without moving their heads and keep them level even when turning sharply in flight so they never lose track of their victims.
Sadly today the survival of many of our dragonfly species is uncertain. Since 1950 three species have become extinct and a third of the 42 found regularly in Britain are now under threat. The loss of wetland habitat due to housing development and intensive agriculture, coupled with run-off and wind drift from insecticides and herbicides, is having a devastating effect on the long-term survival prospects of many of these wonderful insects. Rising sea-levels and diffuse pollution in our waterways also threaten their long-term survival.
In the UK one of the best places to see dragonflies is at Wicken Fen in Cambridgeshire, where 21 species of dragonfly breed on the fen, and where an exciting new national centre dedicated to these unique insects opens today.
The Centre will open at weekends throughout the summer offering a regular programme of events including dragonfly safaris, talks to beginners and advanced courses on dragonfly identification and biology for uber-geeks like me. It'll also offer practical advice on wildlife gardening and pond creation - making it the perfect place for anyone can learn how to help protect dragonflies for the future.
• Chris Packham is an author, photographer and the presenter of BBC's Springwatch