Emperor Dragonfly

28 August 2018 | Posted in Charlotte Owen , Insects
Emperor Dragonfly
Emperor dragonfly © Neil Fletcher

By Charlotte Owen

WildCall Officer

Dragonflies are spectacular insects.  As they dart and glide across the summer skies with a bright flash of iridescent colour and a whirr of wings, it’s easy to see how they earned their name.  They are voracious aerial predators and exceptionally agile: all four wings operate independently, allowing a dragonfly to dart off in any direction and make rapid alterations to its flight path as it chases down its prey.  At top speed, some species can reach up to 30 miles an hour and accelerate with such power that they experience the same kind of G-force as a jet fighter pilot.

Dragonflies are also amongst the most ancient of creatures, and their ancestors first took flight more than 300 million years ago.  The fossil record shows that some reached truly gigantic proportions, with wingspans of up to 70 cm, making them the largest insects that ever lived.  Today’s dragonflies may be significantly smaller but they are just as magical, and Sussex is a particular hotspot.

One of our most impressive species is the Emperor, aptly named because it’s our largest (with a wingspan of 10 cm) and the males are highly territorial.  Adults first emerge in June and are on the wing right throughout the summer, usually until early September.  Males have a bright blue abdomen and contrasting apple-green thorax with striking blue eyes, whereas females are much greener all over.  Both sexes have a distinctive black stripe along their backs but it’s probably their impressive size that you’ll notice first.

The Emperor often flies high up as it hunts for insect prey, including butterflies and even smaller dragonflies, but this species doesn’t stray too far from water.  The female will lay her eggs on pondweed and other plants and is likely to visit garden ponds, lakes, gravel pits and canals with plenty of aquatic vegetation.  The male tends to be on constant patrol and will rarely ever settle.  He rules with an iron fist, aggressively chasing away any intruders that venture too close and even taking on small birds.  Aerial ‘dog fights’ between rival males are common and these astonishing acrobatic displays test their flying skills to the absolute limit.  

Comments

  • Richard Barrick:

    07 Sep 2021 06:38:00

    Two days ago Sept 4th, we had an Emperor Dragonfly in our house at Mortlake about 1/3rd of a mile from the Thames. With our rear doors open to our small garden, insects fly in all summer but due perhaps to our glass ceilinged kitchen, are attracted upwards and can rarely find their way out to freedom. A few days ago there was an unusually loud sound of insect wings and I was surprised to see and enormous dragonfly flying two and fro under the glass ceiling. After five minutes stood on a chair I managed with a large bowl and A4 paper ‘lid’ to catch it and take it to freedom outside where it happily flew off. My impression was not of any blue but of the bright apple green thorax. A female? Certainly large- probably 4 inches across its wings.

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