This Ashy is from Favorite Flies by Mary Orvis Marbury (1892)

Mary did not give a recipe for this fly except to say it was used to imitate caterpillars and tied with either a red or orange body and light dun or light ash hackle. She said light dun / light ash hackle feathers were worth their weight in gold because of how rare they were in the late 1800’s.

   

Use a dry fly hook of desired size
Lay down a base of black thread (per the illustration by Charles Orvis that shows a black head)

Tie in a dun hackle with fibers shorter than the hook gap by the tip shiny side out at the hook bend

   

Dub an orange body

   

Palmer the hackle in spiraling wraps over the body (tie off, clip extra)

Tie in and wrap a tight front hackle with fibers 1.5 hook gap; tie off; clip butt stem

   

Wrap in a black thread head

   

Whip finish; head cement