Viewing large in lightbox (hit "L") really brings out some cool detail. Shot with a Canon 50mm f/1.8 with 21mm of extension tubes. Thanks to ok2smile for some incredible advice on how to use DOF preview to trick my lens into staying at f/8 when on my entry level, no connection extension tubes. See below where I set that wisdom out at length.
Focus was on manual, but achieved by swaying back and forward like a seasick porcupine. No small number of frames taken to get one sharp one that way, but it seems to work much better and keeps hands away from the front of the lens. I would guess this was shot about 8cm from the bees, so manually focusing on the ring would certainly have spooked them.
It's my first non-abstract macro posting, and hopefully supports the argument that an £80 lens and £5 tubes (and a £5 lens hood) shouldn't be judged on price alone.
Notes - if you have low end extension tubes with no electronic connections to the body and lens on either side, and if your lens lacks the manual aperture ring (as most modern lenses do), then you will always be shooting at your widest aperture. This is because normally your camera treats you to maximum light for the viewfinder (widest aperture), then electronically narrows it as commanded when the shutter is clicked. Without contacts, it can't send that command. The danger is this can create so narrow a plane of focus that your macro shots lack sharpness across the subject. To get round this, set the aperture as desired (I am finding f/8 useful), then press your DOF preview button - this narrows the aperture. Keeping the DOF preview button pressed, remove the lens. Looking into the lens you will see the aperture remains contracted.