Southern Damselfly (Coenagrion mercuriale)

Size: - Approximate Length 30mm - Wing Span 34mm.

Male: - Another blue damselfly with black markings. The slightly elliptical spots just behind the eyes are separated by a blue bar. The antehumeral stripes are fine unbroken blue lines. Abdominal segment 9 is 80% black, segments 3 & 4 display a black lanceolate mark with the point towards the head.

The most distinguishing feature is the “mercury” mark on segment two. This mark is somewhat variable both

This narrative was kindly written and supplied by Mr Ken Crick

All Photography by Chris Brooks

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within and between site specific populations.

Female: - The female closely resembles its Azure counterpart, the presence of a bar between the spots behind the eyes being the only immediately obvious difference.

Status: - This species has a distribution that is limited to parts of Wales, Devon & Hampshire. This species is under the protection of the Wildlife and Countryside Act of 1981.

Habitat: - Found on flowing water, flushes and small streams, which are fed by underground water sources with an almost constant water temperature.

It tends to favour both the calcareous water meadow ditch systems and shallow heathland streams which have an open aspect.

Flight period: - Mainly June and July.

General: - For those familiar with Azure & Common

Blue Damselflies the smaller size of this species is clearly apparent. It is rarely if ever is found in the presence of other species of blue damselfly. The Small Red damselfly is often found alongside the Southern Damselfly, the females are very similar but can be distinguished from one another by careful observation of the coloured lines separating abdominal segments 7,8,9 & 10, which are red for Small Red and blue for Southern Damselfly.