Small hoverfly

Small hoverfly

Observation - Small hoverfly. Description: I think these are the same species - quite a few of them around a pot of violas, though they didn't seem interested in visiting the flowers, just guarding them from each other. Just over 1cm long. They usually landed with wings spread out, then flicked

I think these are the same species - quite a few of them around a pot of violas, though they didn't seem interested in visiting the flowers, just guarding them from each other. Just over 1cm long. They usually landed with wings spread out, then flicked them in over their backs. I tried matching them with photos, but they seemed similar to all of these: Dasysyrphus, Eupeodes or Syrphus. Am I anywhere near?