I don't think this is Amenia imperialis ... it doesn't seem to have a yellow head, and it lacks spots on the abdomen. It looks a bit more like one I saw yesterday, which I'm tentatively calling Rutillia ... what do you think? Unidentified on 2 Feb 2019 James may be able to confirm these for us.
The way that the eyes aren't bulbous, but rather, wrap around continuously with the spherical/ovoid profile of the head make me think this is closer to Chrysomya. Also, the body segments have a more constant cylindrical shape, rather than being robust, and the metallic banding on the (dorsal) abdomen is broken on T3 but not T4 - thats unlike any Rutilia or Amenia i've seen, although I guess its possible. It's a challenging call because we only have a single angle at poor resolution, but I'd wager this is most likely a species of Chrysomya, or something completely unrelated, like a metallic Strat or Syrphid. You just can't see any of the key characters (wing venation, antenna, face).
Thank you to both of you! Alas, this little guy flew away before more could be taken, and these from some distance with a 200mm lense. If when exploring this area again, and happen upon it, I will attempt to get other angles for better identification. Thank you both once again! Jules