A beautiful wasp-mimic hoverfly

While in the wildlife garden a couple of days ago, I noticed a large boldly marked hoverfly male hovering by the pond. I managed just a couple of shots, but this one is enough to identify it as Chrysotoxum festivum, a relatively scarce hoverfly in the north of England. Unlike other hoverflies, this genus has long, forward-pointing antennae, which contribute to liken it to a wasp. There is little information on the biology of this genus, although the larvae have been found inside ants nests, where they presumably feed on ant-attended ground aphids.