Perthshire Wildlife

Aug 04

Perthshire Wildlife - Dragonflies

Posted on Tuesday, August 04, 2015

It’s early August and although this is meant to be one of the warmest months of the year, the Met office says we are enjoying the sort of temperatures that we would normally expect in October. Which probably explains why we didn’t see many dragonflies on our dragonfly walk this morning!

I decided to write about dragonflies for the summer blog as they are one of the species that we associate with warm, sunny days. They can usually be seen flying around water bodies – ponds, lochs, canals, burns and rivers - and in the Perthshire area we can expect to see at least ten species.

Dragonflies have an amazing life cycle and lots of people aren’t aware that dragonflies (and damselflies) actually spend most of their life as larvae underwater, with some species living there for up to five or six years. Golden-ringed Dragonflies live in upland burns where temperatures and food availability are relatively low, so take the longest of our dragonflies to reach adulthood. The female lays her eggs in the bed of the burn and because she needs to lay them deep in the substrate, she looks a bit like a pneumatic drill when laying them. The eggs hatch into larvae, which live in the bed of the burn and feed on small invertebrates such as midge larvae, water fleas and freshwater shrimps. As they get bigger they shed their skins and grow bigger ones until it is time to emerge as an adult.

What happens next is amazing to watch – the dragonfly larva climbs up the stem of an emergent plant and its skin splits all the way down the back. An adult dragonfly emerges and spends a few hours pumping blood around its wings and drying out. When able to fly, the adult finds a place to hunt for its insect prey (such as midges and flies) and builds up its strength while developing its adult colours. When it is ready to mate it will return to the water body where the life cycle starts all over again.

Dragonflies and damselflies are unique in forming a copulation wheel whilst mating – this frequently takes the shape of a loveheart! As adults they will live only a few weeks but will manage to consume lots of midges in that time!

If you do see any dragonflies when out on a walk, please let the British Dragonfly Society know. They have a Scottish section to their website where you can see the different species found here, see events taking place over the summer and you can enter your records on the main recording page. See www.british-dragonflies.org.uk

Perthshire Wildlife will be running a number of guided walks around Blairgowrie over the autumn, including the ever-popular Spooky Species for Halloween! More info can be found and tickets for events and walks booked at www.perthshirewildlife.co.uk/events