Eristalis Hoverflies Mating
I couldn't get a shot without some vegetation getting in the way and these are a little soft. However, such opportunities are rare.
Olympus EM-1 (aperture priority), Olympus 4/3 x2 TC, Olympus 4/3 50mm f2 macro, 1/60 at f11 ISO 2,000, hand-held.
The stereo is crosseye.