'And if one greenbottle should accidentally fall'

Backblip. This stunning vividly green fly was feeding on a ragwort flower in the park on Sunday when we took our toddler out picking raspberries. When I was growing up, we would have called anything that looked like this a 'greenbottle' but now I know that it isn't so simple. There are at least three, maybe more, families of flies that contain metallic green flies. I am insufficiently experienced with identifying Diptera (flies) to have any confidence about naming this. I might send it to the iSpot website for some taxonomic assistance! For now, I will just marvel at its metallic green magnificence!