I found this gorgeous big fly around my compost bin last summer. There were about 4 of them flying around for a few days and then they vanished. I had no idea what it was and after fruitless searching, sent it to the good folk at Bug Guide, who immediately told me it was a Solder Fly (Stratiomyidae) and in the genus Ptecticus. The only members of this family I am familiar with are the ones in the Genus Stratiomyia, so this was a new one for me.