Hook: Dry fly, 12 to 18
Egg sack: Medium olive hackle, wrapped and trimmed
Body: Dark blue dun hackle, wrapped and trimmed
Wing: Partridge body feather, tied flat on top
Hackle: Medium blue dun and brown
Don't remember where I got the recipe - one of my tying books - but it works.
This fly is a good imitation of the female Brachycentrus, or the "shadfly" of the Delaware. It is called that because it appears about the same time as the shad runs up the river.
I make sure I have some with me when I go out at that time, but the Hendricksons and Quill Gordons are the usual mayflies also hatching then.
That reminds me - I better tie some up soon - after I make up more steelie patterns.