Calopteryx virgo is from the Family Calopterygidae and closely resembles C. splendens (1). The total length is between 45 to 49 mm, it is a relatively large and robust species. Male wings are broad and almost paddle-shaped, the wings are purplish blue but variation can also occur. They have no pterostigma (thickened outer wing cell) (2). The end of abdomen is brown to reddish in colour and extensively marked with black. Females are metallic green and brownish and can easily be confused to C. splendens. Female wings are translucent greenish to deep ebony and sometimes very dark. There is white patch at the tip of the wing which is a false pterostigma (2). Three different variations can be distinguished by wing colour and they are normally treated as subspecies (3). The nymphs are small-headed and they have three flap-like gill filaments.
After mating the female lays eggs in an area where the nymphs will hatch. Nymphs moult several times as they grow. After a time they emerge from the nymphal skin with unexpanded wings. After emerging wings expand as they dry (1). The flight season is from May to late September (3). Hybridisations between Calopteryx virgo and C. splendens can occur.
Flight is reminiscent of that of a butterfly (3). Males are more agile than other damselflies and they display their colours to females during a fluttery courtship dance.
They prefers shaded, small and cool running waters. Usually in small forest streams. The habitat is quite similar to Calopteryx splendens (3).
They are locally common in most of the Europe but absent in large areas in the south, for example in many of the Mediterranean islands. It is also rare to find this species on a plateau (3).
Description written by Aino Helakallio (2009)
(1) McGavin. G. (2004) Insects and Spiders, DK Publishing, London
(2) Chinery. M. (2007) Insects of Britain and Europe, A & C Black Publishers, London
(3) Dijkastra, K.D. (2006) Field Guide to the Dragonflies of Britain and Europe, British Wildlife, Dorset