Gemstones on the Senne streams
Dragonflies are perfectly adapted for life in or on bodies of water. The females lay the eggs in the water (or in aquatic plants or in the water bed). The larvae that hatch from it live in the water for a few months to several years. After pupation, the fully grown, airworthy dragonflies hatch from the pupal shell.
Of the approx. 80 dragonfly species found in Germany, only a few are adapted to running waters. Two types of demoiselle live on slowly flowing streams and rivers – including the Senne streams. They are very strikingly coloured and delight us with their blue, green and brownish shimmering bodies and their slightly fluttering flight. Like all other dragonflies, they also feed on small flying insects. The larvae that live in the water are also predators: They hunt small crabs and insect larvae.
In the case of the two native species, males and females can be easily distinguished. In the blue-winged demoiselle, the wings of the males are completely blue and those of the females are light brown. In the banded demoiselle, the wings of the males wear a wide blue band and those of the females are pale green. The females of the demoiselle lay their eggs in the male’s territory. The larvae live in the water for 1–2 years until they hatch out of the larval skin on plants outside the water. The adult animals only have about 1 month to reproduce. Demoiselle are not very active in flight and often stay close to the location of hatching.