Dragonflies and damselflies belong to the group (or Order) of insects known as Odonata, a primitive and successful group whose ancestors emerged more than 300 million years ago, and is largely unchanged today. They live in a broad range of environments and can be found on every continent except Antarctica.
Like all insects, they are invertebrates with a body divided in three distinct sections: the head, thorax, and abdomen. They have three pairs of segmented legs, a pair of large compound eyes and a pair of small antennae.
Today there are about 7,000 species of Odonata, divided into two distinct groups or sub-orders: Anisoptera (the true dragonflies) and Zygoptera (the damselflies). There are slightly more dragonfly species than damselflies.
In the UK, the term ‘dragonflies’ is often applied to all Odonata, including damselflies. This makes the distinction between true (Anisopteran) dragonflies and damselflies difficult at times! Some suggest calling Anisopteran dragonflies ‘Warrior flies’, but in the UK at least this hasn’t gained much ground. To help avoid this confusion we generally refer to Anisopteran dragonflies as dragonflies, Zygoptera as damselflies, and the whole order collectively as Odonata.
Odonata, and dragonflies in particular, are superlative fliers and able to fly seemingly indefinitely (they do land though!), they can hover, fly forward, backwards and sideways and change direction endlessly as they chase prey at great speed or seek a mate.
Humans don’t exploit Odonata commercially on any large scale, but in some cultures, they are used for medicinal purposes, and they can be a snack or a delicacy at the dinner table. But although there is little exploitation, they are especially useful as ecological indicators.
Dragonfly and damselfly larvae require clean, unpolluted, waters to thrive, and it follows that their presence is a good indicator of water quality. As adult airborne insects they require that the surrounding environment is free from pesticides, and that it supports a variety of flora and fauna which in turn supports the insect life that Odonata feed upon.
With increasing awareness then, we realise Odonata are sensitive indicators of environmental quality and play a key role in demonstrating that habitats are responsibly managed and are sustainable. This is a primary conservation aim and is of benefit to us all.
While dragonflies can be abundant in some environments, they are susceptible to the human impact of pollution, habitat mismanagement and environmental catastrophe.
This is especially true when they have specialised habitat requirements; following accidental pollution of their only breeding site during the 1960s, the Norfolk Damselfly became extinct in the UK. In Bedfordshire the Scarce Blue-tailed Damselfly became extinct with the loss of its last breeding ground at Sundon Chalk Quarry.
Of the thousands of species worldwide only 46 or so are common to the British Isles and just over half of these occur in Bedfordshire.
Climate change is likely to effect Odonata distribution and over the last 20 years more species are visiting and establishing breeding colonies, both in the UK and Bedfordshire. We also attract migrants and vagrants from time to time, and new species may turn up. Whether these movements are long term range expansions or not remains to be seen, but the world of dragonflies and damselflies is constantly changing.