Two unknown insects, perched on a rose stem

While prowling around the garden with a macro lens I spotted two patches of yellow which turned out to be abdomens. I crouched down to try and get a stable shot but didn't recognise the insects I'd found.

I wonder whether they are a variety of hoverfly, which very often is the answer to this sort of question as apparently there are thousands of hoverfly varieties. I may get an ID from a blipper, but I'm not holding my breath, as I was doing whilst bending down to photograph them.