Ribbing Brown permanent marker (perdigon body thread)
Hackle Natural grey + mayfly yellow (CDC in split thread)
Wings Mayfly yellow (mallard)
How to tie it
Lay a yellow thread base to the bend and tie in pheasant tail barbs as the tail.
Tie in the brown perdigon body thread for the rib, then wrap a CDC feather in mayfly yellow forward as the body to the 65% mark.
Rib forward with the brown thread in open turns, wrapping against the direction of the body feather locks the CDC in place and stops a trout unravelling it on the first take.
Tie in mallard dyed mayfly yellow as the wings, set upright over the thorax.
Load a split thread with CDC in natural grey and mayfly yellow, spin it into a soft rope and wrap it as the hackle. The split-thread hackle gives a broad, light footprint without the stiffness of a cock hackle.
Whip finish a small head. The fly should sit down in the film on its CDC footprint, not perched on hackle points.
Other versions
2 more in the app: Lucian Vasies (2), Lucian Vasies (3).