WD-40
The WD-40, developed by guide Mark Engler on the South Platte, is a genius simplicity pattern that imitates emerging Baetis and midges. Its slim dubbed body, small wing bud, and optional wire rib create a remarkably realistic emerger that trout take with confidence in the film. One of the top patterns on tailwaters throughout the Rocky Mountain West, it shines in the fall and winter when BWO hatches are heavy.
- Type
- emerger (Mayfly)
- Hook sizes
- #18–24
- Target species
- trout
- Difficulty
- intermediate
- Best seasons
- spring, fall, winter
Materials
- hook: Dry fly or scud hook #18–24
- thread: Gray or olive 10/0
- tail: Wood duck or mallard flank fibers, sparse
- body: Gray or olive thread or fine dubbing
- wing: Gray CDC, small wisp
- thorax: Gray or dark brown dubbing
Tying steps
- Mount a size 18–24 hook; optionally slide on a tiny tungsten bead.
- Start gray or olive thread at the bend.
- Tie in 2–3 wood duck flank or lemon-dyed mallard fibers as a sparse tail.
- Wind a smooth, slim body of gray or olive thread or dubbing to the 2/3 mark.
- Tie in a tiny wisp of gray or dun CDC as a wing bud at the 2/3 mark.
- Dub a slightly larger thorax ahead of the wing bud.
- Build a tiny head; whip finish carefully.
- Apply the thinnest possible drop of head cement with a needle.