Mount an Alec Jackson covert nymph hook with a white bead pushed up to the eye. The white bead stands in for the gills of an ascending chironomid pupa, so no separate gill material is needed.
Start fluorescent orange thread behind the bead and tie in small silver Ultra Wire, running the wire down the full length of the shank as you wrap back. Binding the wire the whole way keeps the underbody even instead of leaving a step where the tag ends.
At the very back, catch in the holographic tinsel, then use the thread alone to build the taper forward. Slim at the tail, swelling toward the bead.
Wrap the tinsel forward in touching turns over the taper and tie it off behind the bead. Touching turns are the point here: any gap breaks up the solid holographic sheen that makes the zucchini work.
Bring the silver wire up in open spiral wraps over the tinsel to create the segmentation, tie it off behind the bead and helicopter the tag out rather than cutting it. Spinning it breaks the wire flush with no stub.
Finish with a few turns of the fluorescent orange thread as a hot spot collar between the body and the bead, then whip finish. That band of orange against the silver rib is the trigger that gives the pattern its name.