Fly's story....

This has been a great pattern for me during the March Brown hatch in the North East, especially on the Upper Delaware system.  I find that the best time to fish this pattern, like all emergers, is early in the hatch when the bugs are crawling and wiggling to get out of their shucks.  The March Brown hatch is my personal favorite hatch of the season.  You can expect, on most normal years, to see your March Browns starting to hatch on the upper Mainstem around the 10th of May, although I've seen the hatch done, on hot weather years, by early May.  Average hatch period for the Delaware is May 10th - June 1st.  Look for fish rising semi-aggressively often showing their dorsal fin then tail (no head showing - although that's not to say a fish breaking the surface with their head wouldn't take this pattern).