Invertebrates
Common Blue Damselfly
Enallagma cyathigerum · also called northern bluet
Over a wide, open lake in July, hundreds of common blue damselflies hover low above the water, a haze of bright blue against the dark surface.
Overview
The common blue damselfly, Enallagma cyathigerum, is a Least Concern damselfly of lakes and ponds across Europe, Asia, and northern North America. Its bright blue males, mushroom-shaped abdominal mark, and success on cold, open waters make it one of the most widespread damselflies in the Northern Hemisphere.
A damselfly of open water
While many damselflies stay among reeds, the common blue is often found flying low over the open surface of lakes and large ponds.
Status
Least Concern, widespread and common.
Common Blue Damselfly: common questions
How can you tell a common blue damselfly from an azure damselfly?
The male common blue has a mushroom-shaped black mark on the second abdominal segment, while the azure has a U-shaped one.
Is the common blue damselfly the same as the northern bluet?
Yes, the same species is called the northern bluet in North America.
Where does it fly?
It often flies low over open water, including lakes and large ponds, rather than staying among the reeds.
Where is the common blue damselfly found?
It lives around lakes and ponds across Europe, Asia, and northern North America.