Saw this 1/4" long fly on my Lotus leaf day after day so finally decided to take a closer look. Shot with a macro lens and then blew it up a little farther to discover some pretty neat coloration. From other internet photos it looks like a long-legged green fly from the Dolichopodid family. So they are "beneficial predators" and very common in the Eastern U.S. both around ponds and crops.
