Moved from Small Minnow Mayflies.

I'm reasonably sure that this is the male imago of Cloeon dipterum. The apparent lack of hindwings, the abdominal markings and coloration, the alternating darker and lighter banding of the cerci, the brown spot on the femora (present in some specimens and absent or indistinct in others), and the short, blunt forceps all seem consistent with the males of this species.

The ovoviviparous C. dipterum is well known to European fly fishers as the "pond olive." ("Olive" or "blue-winged olive" is a general name applied to many baetids rather than reflecting the color of a specific species). They refer to the female imagoes as "apricot spinners." There seems to be no mention of this species in fly-fishing literature on this side of the pond. This is probably due to the species inhabiting still waters, including temporary pools or garden ponds.

Peter-

Species ID would probably not be possible from your photo, but I can tell you with confidence that it's a male imago of family Baetidae.