Emperor dragonfly
Males patrol a length of open water on the wing for hours at a time, chasing off rival males and rarely settling in view.
| Where | Large ponds, lakes, slow rivers and canals |
|---|---|
| Size | 66 to 84 mm body length |
| When | May to August |
Males have a bright blue abdomen with a black dorsal line and a green thorax, while females are greener and become bluer with age.
It breeds in well-vegetated ponds, lakes and slow rivers, and the large aquatic nymphs can take one to three years to develop before emerging.
Traits
Habitat
Wetland
Colour
Blue, Green
Active
Day
To people
Harmless
Activity through the year
Often confused with
The lesser emperor has a brown, unmarked thorax, unlike the emperor dragonfly's bright green thorax.
Questions
Is the Emperor dragonfly dangerous to people?
The Emperor dragonfly is harmless to people.
When can you see the Emperor dragonfly?
The Emperor dragonfly can be seen from May to August, by day.
Plate retouched from a photo by Quartl, CC BY‑SA 3.0, Wikimedia Commons Licence
The plate on this page is shared under the same licence as its source, CC BY-SA.
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Dragonflies and damselflies›Hawkers›Anax
Last updated 2026-09-26. Every entry is checked against published sources.