One of the oldest recorded dry fly patterns, the Blue Dun is a classic Catskill-style imitation for the small blue mayflies — Blue-Winged Olives, Mahogany Duns, and similar species. The dun hackle tips and gray body are timeless.
1. Thread base — Attach gray thread behind the eye and build a base to the bend.
2. Tail — Tie in a sparse bunch of dun hackle fibers at the bend, one hook-gap in length.
3. Wings — At the 2/3 point, select two matching dun hackle tips. Tie in upright and divide with figure-eight wraps, wing tips extending to the hook point.
4. Body — Dub a smooth, lightly tapered gray body from the bend to just behind the wings.
5. Hackle — Tie in a dun hackle behind the wings. Wind 3–4 turns through the thorax area, interleaving with the wing base. Tie off and trim.
6. Head — Build a small, neat head. Whip finish and apply head cement.
hook
thread
tail
wing
body
hackle
Baetis spp.
Paraleptophlebia spp.
