Banded demoiselle  (Calopteryx splendens)

The banded demoiselle is classified as Least Concern (LC) on the IUCN Red List (1).

A striking species of damselfly, the banded demoiselle (Calopteryx splendens) has the same style of butterfly-like flitting flight as that of the beautiful demoiselle (Calopteryx virgo) (3). The male banded demoiselle has a metallic bluish-green body with a central band of blackish-blue pigment on the wings. The female is metallic green and lacks the band on the wings (3).

The male banded demoiselles can be distinguished from males of the similar species, the beautiful demoiselle, as the latter species lacks the distinct band of pigmentation on the wing (4).

There are a number of different subspecies and forms of the banded demoiselle, which differ in the shading of the wings (1).

The banded demoiselle is found in central and southern mainland Europe (2), across Asia to China (4). In Britain, this species occurs mainly in the south and midlands, but there are a few scattered populations in the Lake District (3).

You can view distribution information for this species at the National Biodiversity Network Gateway.

The banded demoiselle inhabits slow-moving rivers, ponds and other still water-bodies (2), with a preference for relatively clear waters (5). This species also requires sunny patches and the presence of abundant emergent aquatic vegetation (5).

The larva of the banded demoiselle occurs among the roots and lower reaches of aquatic plants, usually close to the bottom of the water column. Active mainly at night (3), the larvae are effective predators with the fascinating feature of being able to fire out the lower portion of the mouth, known as the ‘mask’, in order to grasp passing prey (5). Larval development takes around two years in the banded demoiselle, and the larva overwinters twice in the mud at the bottom of the river or pond (3). When it is ready to emerge as an adult, the larva will often travel up to 100 metres out of the water, and typically complete its emergence in a shrub or tree (3).

After emergence, the adult banded demoiselle takes seven to ten days to mature, and the flight period of the adult is between May and the end of September (2) (4). The male banded demoiselle will establish a territory around a suitable egg-laying site, which usually includes abundant vegetation protruding from the water (4). The male may actively court females with a fluttering display flight (3), and then lead them to a suitable egg-laying site (5). After mating, the female will oviposit alone, often placing the eggs into the tissues of submerged vegetation (4). The eggs take around 14 days to hatch (3).

While the banded demoiselle is considered to be widespread and common, it nevertheless faces a number of threats. Habitat loss and pollution of its freshwater habitat are problems currently facing this species throughout its range (1).

The population trends of the banded demoiselle are currently being monitored, and this species may also benefit from general plans to conserve freshwater habitats (1).

View information on this species at the UNEP World Conservation Monitoring Centre.

There may be further information about this species available via the National Biodiversity Network Gateway.

Learn more about the banded demoiselle:

• BBC Wildlife Finder:
  http://www.bbc.co.uk/nature/species/Banded_Demoiselle

For more information on dragonflies and damselflies:

• The British Dragonfly Society:
  http://www.dragonflysoc.org.uk/

For more on invertebrates and their conservation:

• Buglife, the invertebrate conservation trust:
  http://www.buglife.org.uk/