Help identifying a biting fly?

Hi! We were in Disney World last week on Tom Sawyer’s Island. While there, this strange green fly bit my wife 3 times. The wound formed a pocket that eventually burst leaving a painful hole at each spot (about the circumference of a pen cap). The wounds are a nuisance and slow to heal (she got hit last year too). The skin around them is inflamed. Last year we thought a fire ant got her, but we never saw the culprit. This year we saw him. Any idea what this fly might be? No more trips to Tom Sawyer’s Island…