René Harrop's WD-40 is a masterclass in minimal fly design — wood duck legs, dubbing body, and snowshoe rabbit wing suggest a midge pupa or BWO emerger just below the film. One of the most effective tailwater nymphs ever created.
1. Thread base — Attach olive thread to the hook and build a smooth base to the bend.
2. Tail — Tie in 2–3 sparse wood duck flank fibers at the bend.
3. Abdomen — Dub a very slim, smooth olive abdomen from the bend to the midpoint.
4. Wing — At the midpoint, tie in a tiny clump of snowshoe rabbit foot hair flat over the thorax, pointing rearward.
5. Legs — Tie in 1–2 wood duck flank fibers on each side at the wing tie-in point to suggest legs.
6. Thorax — Dub a slightly fuller gray thorax from the wing area to just behind the eye.
7. Head — Build a tiny head. Whip finish and apply head cement.
