Wing Two matching wood pigeon secondary quill slips
Hackle Starling shoulder feather (a small black hen hackle is given as an alternative)
How to tie it
Tie in a few crow secondary fibres for the body.
Wind the crow fibres forward with hackle pliers to make a slender body, then swap back to the tying thread, take one turn over the fibres to lock them and trim off the waste.
Tie in two matching wood pigeon secondary wing quill slips, back to back, long enough to reach back to the end of the hook, and trim the butts.
Prepare a starling shoulder feather and tie it in by the tip, with a turn behind it to pull it away from the hook.
Wind the starling hackle with hackle pliers, tie it off, trim, and whip finish.
Put a coat of varnish on the head.
Other versions
2 more in the app: Consensus of Savage Flies (Leisenring's Black Gnat) and The Bulletin, As tied by Hubert Janeczek.