White Legged Damselfy (Platycnemis pennipes)

Size: - Approximate Length 36mm - Wing Span 45mm.

Male: - Creamy white just after emergence, males mature to a pale pastel blue. The upper surface of the thorax has one full length wide antehumeral stripe either side of the centreline. Parallel to this is a second fine stripe; on some specimens this fine line is interrupted by the black outline. On the upper surface of each abdominal segment is a longitudinal line that thickens and splits on segments 7 to 10. These black lines seem to become more intense with age.

This narrative was kindly written and supplied by Mr Ken Crick

All Photography by Chris Brooks

Click on the thumb-nails to enlarge the images.

The tibias of the mid and hind legs are broad white feather like structures and the source of the vernacular name.

Female: - The near white immature females have brown eyes; each abdominal segment has a pair of dark spots to the rear. With increasing maturity these spots develop into parallel longitudinal lines split by a fine line of the dominant background colour. The female darkens slightly with age to a bleached straw with possibly a hint of green.

Status: - This species is confined in the British Isles to areas of England south of the wash. Even here quite large regions seem unable to support this species.

Habitat: - Unshaded slow flowing rivers and canals with floating and emergent vegetation. Also found on stream fed and drained lakes containing carp.

Flight period: - Late May to mid August.

General: - Mating takes about thirty minutes and eggs

are laid on the underside of floating leaves and into the stems of emergent vegetation. Larvae live on the bottom of the water body among the rotting leaf litter.

Adult emergence can be highly synchronized, with large numbers taking to the air all at once, when tall vegetation used for emergence is disturbed. Males are territorial and use their feathery legs both as a threat display and for attracting females.