Widespread and common. Adults can be seen between May and August according to locality. Similar in habits and distribution to its close relative C. pulchellum. C. puella is less common than it on cutover bogs and mesotrophic lakes, but more common on eutrophic sites. A lowland species avoiding exposed and upland sites, as well as all but the slowest flowing rivers.

The male Azure Damselfly is similar to the Variable Damselfly Coenagrion pulchellum and the Common Blue Damselfly Enallagma cyathigerum but can be distinguished by the characteristic black U-shaped marking which does not join up with the black ring at the posterior end of the second abdominal segment. In the female Azure damselfly there are two colour forms, blue and green. The blue form is similar to the female of the Variable Damselfly Coenagrion pulchellum but can best be distinguished by examining the shape of the pronotum. It can be distinguished from females of the Common Blue Damselfly Enallagma cyathigerum by the absence of a spine below the 8th abdominal segment.

KEY IDENTIFICATION FEATURES

• In males there is a characteristic black U-shaped mark on the second abdominal segment which is separate from the black ring at the bottom of the segment
• In segments 4-6 there is more blue/less black in comparison with Coenagrion pulchellum
• In males the blue dorsal thoracic stripes are always complete and only slightly waisted
• The hind margin of the pronotum is broad and flattened (see comparison of pronotums of blue damselflies)
• Females are best identified by examining the shape of the posterior lobe of the pronotum
• In females there are two black stripes on the side of the thorax
• There is no spine below the 8th abdominal segment