The large red damselfly (Frühe Adonisjungfer / Pyrrhosoma nymphula) is a small damselfly whose German name is due to their early appearance. There is only one other red-coloured damselfly in Central Europe and both are quite common but rarely seen, because they hide well.
More interesting for me: On the belly and on the back of this damselfly one might suspect a clutch of eggs. However, these are lots of ectoparasitical* larvae of water mites (probably an Arrenurus species) which bite into the dragonfly while hatching and suck the blood of the host. If they are filled to the brim, they fall of.
* Ectoparasites live on the surface of the host. They feed on skin substances, tissue fluid or like in this case, they take blood.
fabulous detail. I've tried photographing them and they (like dogs and cats and birds) all have that sense which tells them to fly away at the moment the shutter is pressed. The biology of the mites is fascinating.
