Hoverflies are the best known wasp and bee mimics, which do an impressive impersonation of their more dangerous distant cousins.
Many hoverflies have evolved these black and yellow ‘don’t mess with me’ markings, but are just bluffing – they are completely harmless.

Gasthaus Moosegg, Pfänder Mountain, Bregenz, Vorarlberg, Austria, 1 August 2020