Here is the fly pattern sheet for Stalcup’s Emerging Dun.
TMC 101, sizes 16 – 22
8/0 UNI thread gray
Tail & Legs:
Gray goose biot
Gray Fine & Dry dubbing
Stalcup’s Emerging Dun can be found Shane’s Mayflies “Top to Bottom”. He includes variations in tan, brown and yellow.
Here is a link to a Youtube page from my friend John Sherry – Netknots Fly Fishing of Shane tying the fly.