Golden-tailed Leaf-walker Xylota sylvarum
Apparently a common species but I don't recall seeing one (or anything like it) until I encountered this one. Such a big and beastly creature I didn't immediately recognise it as a hoverfly - it had that slightly intimidating feel of a horsefly...
Golden-tailed Leafwalker Xylota sylvarum, Elmham railway (Norfolk, UK), 3rd June 2022