#3
Thank you for the identification of the genus!
I found that six species occur in Germany:
A. plumbeus
A. atroparvus
A. algeriensis
A. claviger
A. maculipennis
A. messeae
A. plumbeus seems to live in waterholes of tree branches, so I assume its not that species.
A. atroparvus lives mostly at the sea, so it probably isn't that species either
So it is either of the remaining four.. Seems it ends here, but the genug already is good to know.