after a few days deprivation increases mortality rapidly, and after again prevail acceptable oxygen conditions, it is still too long after, birth defects and an increased mortality rate among affected animals. This is mainly because they absorb the oxygen from the water inefficient. Was able to detect in experiments that even larvae of the banded demoiselle, who had been removed completely. The thin-skinned, tracheogenic body attachments for oxygen uptaking from the water, under normal circumstances are still less sensitive to fluctuations in the oxygen supply. The inefficiency of oxygen uptake is balanced by the choice of habitat, since both increased flow and cooler water absorption capacity. Hatching The first adults of dragonflies emerge, depending on the weather, at the end of April to the end of September. The main hatching time lies in the days of late May to late June. The emergence, i.e. the transformation of the larvae to adults and the associated leaving the water, is not synchronous and lasts throughout the season until about mid-July. The newly hatched dragonflies spend after leaving the larval shell (exuvia ) is the first time until full coloration in the vegetation surrounding the water body. This aging period usually lasts about 10 days, after which they return to the waters. The adult animals live only one season, it was a lifetime determined from about 40 to 50 days. Throughout the day there are males in sunlit waters are already in the early morning (in Central Europe between 7.00 and 9.00 o'clock), where they stay forever in the areas that are exposed directly. In the aquatic environment, shaded according to the animals appear later, usually basking in the tops of the surrounding vegetation. Females fly over during the day, the waters in search of suitable nesting sites, the main activity of both sexes such as hunting, advertising, mating and egg laying occurs in the warm midday hours. At night the animals as well as sit in the early morning sun-drenched coves in the vegetation at these sites, they also spend the night. The radius of action and thus the distance between breeding, hunting and rest area is in the males of 20–100 meters and is therefore very small, the females were observed, however walking distances of up to four miles per day. Conservation The blue wing-demoiselle is stenoecious, due to their very narrow ecological requirements. Especially the larvae can only thrive in