A remarkable, butterfly-like flying dragonfly with metallic blue shimmering wing bars. In the Donau-Auen National Park, the Banded Demoiselle is most likely to be seen on slow-moving backwaters, if only in limited numbers.
Description
A body length of approximately 5cm and wingspan of up to 6 or 7cm. Males have greenish-coloured wings with a broad, blackish-blue iridescent band around them which however does not cover either base or tips. Body is metallic blue-green. Females have greenish-coloured wings and a metallic green body. Both males and females fly like butterflies, mostly along the shore.
Distribution
The full range of this species encompasses nearly the entire Palearctic, from the Atlantic to China. In the National Park, limited to connected backwaters.
Endangerment and Conservation Status
Classified according to the Red List as "least concern" but near threatened in Germany and potentially threatened in Lower Austria. Rare to somewhat frequent in the National Park; found only on free-flowing backwaters.
Behaviour
Males stake out their territory with a strange, whirring flight. Should other members of the species enter their territory, these intruders will be attacked. Eggs are deposited in floating plants; while laying their eggs, females are able to remain submerged under water with their entire bodies if necessary. Larvae have a two-year developmental stage; they may most likely be found in roots around undercut banks, but also on aquatic plants.
Special Characteristics
The Banded Demoiselle has nine different flight patterns: preying, defending, threatening, soaring, and display flights. Mating behaviour is also fascinating: first, males display the yellow-white underside of the tip of their abdomen to females flying by. Then they carry out a courtship display flight which culminates in mating.