The Bileks damselfly(Coenagrion hylas) is probably the rarest damselfly in Central Europe! It is under strictest protection and is the heraldic animal of the Nature Park Tiroler Lech!

Pale blue-black in color, this azure damselfly is distinguished from all other damselflies by a broad black stripe on the sides of the abdomen. From 3 o'clock in the afternoon the Bileks damselfly takes a "coffee break" and moves to the mountain forests. There it finds enough food and proves to be an excellent hunter. It is a true fair-weather flyer. Only in good weather and optimal flight conditions between mid-May and early August can it be observed in flight.

The Bileks azure damselfly inhabits clear mountain lakes that have a cold inflow and outflow. It prefers shallow shore areas overgrown with sedges and horsetails .

Its main distribution area is in eastern Siberia. "Siberian azure damselfly" it is therefore also called. In the Alps, about 8,000 km away, it has found its second distribution area in Austria and here mainly in the area of Lake Rieden.