Dragonflies., from our very own garden pond!

Possibly a Southern hawker ( Aeshna cycnea )

 Just emerged from lava case

 Ready to fly

Some of the more than 30 lava cases recovered this summer from the pond just 2.5m by 1.5m

Curry Rivel Wildlife Survey Group report.

Good year for DRAGONFLIES

We all know and admire the beauty of dragonflies and those of us with garden ponds will have the pleasure of seeing damselflies hovering over the water on sunny days.  This charming species is very ancient, around 300 million years old as fossilised remains have proved.  So, a very successful insect perhaps because in contrast to their beauty they are aggressive, carnivorous predators during their short summer lives.

Dragonflies are recognisable to most of us in two groups - dragonflies and damselflies.  Dragonflies are the larger and stouter and damselflies are smaller and daintier.  When trying to identify them there is one very obvious difference.  When at rest dragonflies keep their wings spread open but damselflies keep them folded together along their backs.  Otherwise they have the same characteristics and only differ in where they hunt and where they tend to lay their eggs. 

 All of them need to be near water but certain dragonflies (known as darters or hawkers) will hunt along hedgerows or at woodland edges.  To catch their prey dragonflies are known to fly as fast as 60 mph!

Eggs are laid in water, mud or in waterside plants.  These eggs hatch into larvae which sometimes remain in their watery birthplaces for several years feeding on all sorts of underwater prey including small fish and frog spawn.  When weather and temperature conditions are just right they emerge, climbing up the stalks of water plants and start to change into their adult form.  Once able to fly they immediate look for mates and start the whole process again but within 2-3 weeks they have completed their work and die.

Dragonflies are usually seen on sunny, warm days when there is plenty of food about but in poor weather they will stay hidden sometimes hanging underneath leaves (perhaps sheltering from our frequent rainfall!).  As with all animal life poor conditions and lack of food sources will affect the survival of dragonflies and indeed there are some that are now giving cause for concern. In fact dragonflies are an indicator species because of their reliance on healthy water courses.  If dragonflies disappear from a watery habitat then there is something wrong with its ecology.

Water pollution is a serious threat which has reduced where control is possible but is still a danger where thoughtless waste disposal continues.

There are some 30 species of dragonfly and 20 species of damselfly in Britain but identification is not easy because they are only visible for a short time and they can fly very fast.  Nowadays with camera phones perhaps it is possible to take a photo for later identification.  There are a few websites devoted to dragonflies e.g. www.british-dragonflies.org.uk  where you can find more information.  Identification is not necessary for most of us to enjoy the sight of a dragonfly with its fragile shimmering wings and striking body colours.  If you find them in your garden you know that you have created a healthy habitat and many other invaluable insects will want to join them.