Banded Demoiselle
(Calopteryx splendens)

Like its stablemate the Copper Demoiselle (Calopteryx haemorrhoidalis) the Banded Demoiselle is a large damselfly, with a body length of 4.5 cm and a wingspan of 6.5 cm. But unlike haemorrhoidalis, whose body colour is metallic bronze-green, the Banded Demoiselle male is a shiny metallic blue (), while the female is an equally shiny metallic green () and has white pseudopterostigmas near the tips of her densely-veined wings. The male's wings too are densely veined and they carry a dark band which runs from the node almost through to the wingtip. Here in Italy we get a subspecies called Calopteryx splendens caprai. The main difference between it and the nominate species (C. s. splendens) lies precisely in the colouration of its wings; in C. s. caprai the blue extends virtually all the way to the wing-tip, whereas in the nominate species it stops well short of the tip and creates the coloured band which gives the species its common name.

Calopteryx splendens flies from mid May to late September, with a peak in July and August. This largely coincides with the flight period of the Copper Demoiselle.

The Banded Demoiselle is a common species which occurs throughout much of Europe. Its favoured habitats are relatively slow-flowing streams and rivers with clean water.

From our own observations we'd describe Calopteryx splendens as 'The Jewel by a Mile'; it is such a splendid insect it will grace any ecosystem by its sheer presence. Its flight is butterfly-like and its metallic body reflects the sunlight to quite a dazzling effect.

At our favourite streams and rivers, we've typically seen whole groups () of Banded Demoiselles flying together. The males as well as the females have their own private perch from which to overlook their section of the river. Fights between rival males are frequent but never physical; Banded Demoiselles seem to have developed a fully ritualised way of resolving conflict.