Emperor Dragonfly Fact File
The emperor dragonfly is one of the largest species of dragonfly found in Europe with their range also covering Africa and Asia.
With their four large wings they are able to fly backwards, up and down or hover giving them the ability to manoeuvre well in the air. This helps them to catch their prey of insects which are caught in the air and eaten while in flight.
At birth the young are larvae which spend the first year or two of life in a body of water. They will then molt their exoskeleton and turn in to the adult dragonfly before flying away.
Learn more about these incredible insects by reading on below.
The emperor dragonfly is sexually dimorphic with males having a bright blue abdomen and green thorax. Females are green across much of their body with a dark stripe down the middle of the abdomen. The legs are brownish black and yellow.
When in flight their abdomen has a slight downward curve.
Their large compound eyes are formed from multiple optical units known as ommatidia. As many as 60,000 units may make up the eye giving them sight similar to ours but without the same definition.
The eyes are adapted for sight at short-distances. These are green or blue in color.
Protruding from the body are four wings which appear to be transparent with thin, black lines criss-crossing them. Each of these wings is attached by a separate muscle which gives them a large range of movement.
An average emperor dragonfly will measure 8cm (3.2in) long. These have a wingspan of 10.6cm (4.2in) across.
Emperor dragonflies are carnivores. They feed on invertebrates such as butterflies and tadpoles. These animals may also feed on smaller species of dragonfly.
The larvae feed on small pondlife.
If they capture small prey it may be eaten while in flight. When capturing prey in flight they will form a basket with their legs to hold the food.
Emperor dragonflies can be found in Europe, Africa and Asia. Climate change has been increasing their range northwards as weather warms. This has allowed them to expand in to Scotland on the British Isles.
They make their home near water courses such as ponds, lakes, canals and rivers. These are typically large bodies of water with large amounts of vegetation.
While primarily found in freshwater they have shown a tolerance for brackish water.
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Egg laying takes place alone within floating pond weed. Eggs hatch roughly 3 weeks after being laid.
They spend between 1 and 2 years in their larval stage. All of the adults emerge within the same 40-50 day period. Emergence occurs at night time.
At birth a dragonfly is known as a nymph and lives in the water. Here they will molt their exoskeleton as they grow. This continues for two years as they continue through a range of instars.
For their final molt they will leave the water and cling to a waterside plant where they shed for a final time and develop the wings they will use to fly.
Males mature within 12 days followed by the females within 13 and 16 days. Breeding begins 9 days after this following which females move to the water to lay.
In flight dragonflies can reach speeds of up to 50km/h (30mph). Flying occurs between June and August.
When hunting the emperor dragonfly is able to move backwards, upside down or hover.
Males are highly territorial and make great efforts to defend their territory.
Predators and Threats
Bee-eating birds are a common predator of the emperor dragonfly.
In parts of their range the emperor dragonfly is considered a delicacy.
While considered of least concern this species is threatened in some parts of its range by habitat destruction and water pollution.
The emperor dragonfly is also known as the blue emperor.
Emperor dragonflies are among the largest dragonfly species in Europe.
These animals have been featured on a number of stamps of countries across their range.
Alandmanson, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons
Quartl, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons
böhringer friedrich, CC BY-SA 2.5 <https://creativecommons.org/licenses/by-sa/2.5>, via Wikimedia Commons
Isiwal/Wikimedia Commons/CC BY-SA 4.0, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons
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