Aphylla williamsoni (Two-striped Forceptail) ♂.
Size: approx. 100 mm. Photo: 08/18/11, 9 am.

A Clubtail with a characteristic forceps-like tail. In Florida, the Two-Striped Forecptail (Aphylla williamsoni) is the only species in this genus. It has a yellow "W" on the front of the brown thorax and two greenish-yellow stripes on each side. The wing stigmas are pale brown. The eyes are blue-grey and the face is yellow with brown cross stripes. This is a male with characteristic yellow flanges on S8. 

bug guide (this photo):