National Insect Week returns in 2020
Dragonflies & damselfliesDamselflies are similar to dragonflies, but hold their wings vertically above their body when at rest. Adults of damselflies and dragonflies are found near freshwater and all species have large eyes.
The Banded Demoiselle is 42-45 mm long, with a wingspan of 60-65 mm.
Banded Demoiselle males have a metallic blue-green body and the wings have a broad band of dark bluish colouring in their outer third.
The females have a brilliant metallic green body and their wings are tinted green (each wing also has a tiny white spot near its tip).
(The Beautiful Demoiselle (Calopteryx virgo) is similar, but its males have wings that are dark all over, not just in a central band, and its females have a brownish tinge to their wings.)
The Banded Demoiselle is found flying over rivers, streams and canals with moderate to slow flow, with beds of silt or mud, or resting on the waterside vegetation.
Adults are found flying from mid-May to September. If you see one, why not send your record to the Banded Demoiselle survey?
Mating lasts one to two minutes, after which the male will guard the female while she lays eggs on or in the leaves or stems of aquatic plants. The eggs take about two weeks to hatch, and the nymphs live underwater amongst roots or aquatic vegetation, usually for two years. When the nymphs have finished development, they crawl up the stems of aquatic plants into the air, where they shed their skin and emerge as winged adults.
Banded Demoiselles have a graceful fluttering flight, similar to that of a butterfly, and are usually seen flying over freshwater or riverside vegetation.
The females have to go underwater to lay their eggs! They are able to breathe whilst submerged, thanks to a trapped layer of air between their wings. The females can lay an egg every two to six seconds. Damselflies and dragonflies look beautiful but they are predators, catching other insects in flight when they are adults, and hunting them underwater as nymphs.
The Banded Demoiselle occurs throughout much of Europe. In Britain, it is generally found in lowland areas from the south coast to Lancashire and North Yorkshire.