The populations of these dragonflies in both the Donau-Auen National Park and in the March wetlands are of great national importance. From mid-May to the end of June, this rare species can only be spotted on large oxbow lakes containing ample floating leaves and/or submerged aquatic vegetation, or on reeds and deadwood.
Description
Body length of around 6cm and a wingspan of approximately 8cm. Males and females have dark brown thorax; abdomen is light brown with a broad, black jagged longitudinal band around the middle of the back. At the base of the back wings is a large, black spot.
Distribution
There is no occurrence of the species in Southern Europe. To the west, its range extends to eastern France; to the east, all the way to eastern Siberia and Japan. In the National Park, it is only found on large oxbow lakes containing ample floating leaves or occasionally submerged aquatic vegetation, reeds and deadwood.
Endangerment and Conservation Status
Endangered in Germany but not in Europe generally. Critically endangered in Lower Austria.
Behaviour
Males fly from mid-May to the end of June in even, quick, direct flights some meters from the shore, usually around 50cm above the water's surface. The development of larvae lasts two to three years; first they inhabit the shallow waters near the shore and later they may be found two to four meters deep on the bottom of the body of water.
Special Characteristics
Oviposition is quite interesting for this species: the eggs are released as a small package from the abdomen of the female. Once in the water, the package rolls out to form a string of eggs which are then attached to aquatic plants such as Myriophyllum, Elodea, or to deadwood.