The Banded Demoiselle

The Banded Demoiselle has the grand Latin name of Calopterix splendens , an apt epithet for one of our most splendid insects. Male Demoiselles can be seen in large numbers along many slow flowing rivers and streams in southern Britain from the end of May to August. Their flashy barred wings, metallic blue-green bodies and flitting flight make them unmistakable and strangely reminiscent, in flight, of little blue helicopters.

The males compete for strategic perches along the river in the hope of mating with passing females but scarcity of suitable mates forces them to spend most of their time sparring with each other for territory. When a female flies by she is often chased by a crowd of optimistic males, despite the fact that she may be already mated or in the process of ovipositing.




Male demoiselles competing for perches.

Damselflies, the Zygoptera, are weaker in flight than their more powerful cousins, the dragonflies, the Anisoptera and command smaller territories in consequence. They have stiff bristles on their legs and these are held forward of the body in feeding flight in a sort of basket arrangement, which allows them to catch small insect prey on the wing.



Male Demoiselle.



Female Demoiselles are less flashy than the males but are nonetheless beautiful with polychrome green thorax and abdomen contrasting nicely with navy blue legs.



Female Demoiselle.



This mating position is called the wheel and is characteristic of damsel and dragonflies. The male grasps the female behind the head and tries to induce her to swing her abdomen into contact with his thorax to receive his spermatophore or sperm packet.


Copulating Demoiselles.


The butterfly-like flight is achieved by the extraordinary free rotation of the wings. The male below is coming in to land at his favourite spot.



Male Demoiselle




Summer on the River Lea, Essex.