The CDC Spent imitates an adult mayfly that has mated, fallen to the surface, and died with its wings outstretched flat on the water — the spent stage of the insect’s life cycle. In this tutorial, Scott Jackson ties the pattern using a detached body construction, with the abdomen built off the hook on a needle and then transferred to the shank as a complete unit. Jackson presents it as a technique anglers often shy away from unnecessarily — once the body proportions and segmentation are right, the rest of the fly is straightforward thorax and wing work on the hook.
The body is built on a needle using a strip of white foam roughly three to four millimeters wide with a V-cut at one end. After binding in a small bunch of black cock fibers as tails, Jackson folds the foam back over the thread base in roughly six segments, each set with semi-tight wraps. Once tied, the whole unit slides cleanly off the needle. On the hook — a Kamasan B100 in size 12 — the body is lashed in at the bend, secured with thread and a touch of super glue. A strip of black closed-cell foam is then tied in to form both the wing post and, eventually, the head. The thorax is dubbed with red Lite Brite — Jackson acknowledges this hot spot doesn’t appear on natural mayflies but adds visibility and contrast. The wing is spun in a dubbing loop using two CDC feathers dyed blue dun and one grizzle hen hackle, then swept back.
The black foam is brought forward and over the wing fibers, splitting the wing into two sides — the spent silhouette of a dead mayfly lying flat in the surface film. A few thread wraps secure the foam down, and the leftover stub forms the head. A small drop of varnish soaked into the wing fibers locks the split in place. Jackson is emphatic that the only view that matters on a spent pattern is the one from underneath — what the trout sees from below — not the top-down or side-on view of the angler. He also notes the same detached body method works for daddy long legs and similar patterns by swapping the foam color.
Material List
Hook: Kamasan B100, size 12
Thread: Uni 8/0 (black)
Detached body: White foam
Tail: Black cock fibers
Thorax cover/wing post/head: Black closed-cell foam
Thorax (rear half): Red Lite Brite dubbing
Wing: Two CDC feathers (dyed blue dun) + one grizzle hen hackle, spun in dubbing loop
