So’s not to steal ducksterman’s thread, but his thread did get us curious… :roll:
Wasn’t a Cary Special developed to immi dragon nymphs in the Pacific NW?
Doesn’t the dragon nymph travel the lake bottom to reach shore, while the damsel nymph travels the top of the water column to do the same?
Sorry, still doesn’t answer any of your question “d” and we’re waiting for answers to your question too. 
…lee s.
lee… I think the answer is yes to all of your questions…of course the damsels have to travel up…
I don’t know if Colonel Carey’s wonderful fly was deliberately intended to imitate a dragonfly nymph. It seems to exhibit a lot of characteristics that fish find attractive. The long pheasant-rump hackle fibers have a lot of movement and the colors (at least in many versions (black, brown, olive and those types that use a rump hackle twisted around the hook shank to form a body), represent the colors of many forms of aquatic life.
One of my personal favorites is the Six Pack (one of the only Carey Special variants that has earned and kept its own name). The Six Pack is tied entirely with yellow-dyed pheasant-rump hackle. Dying natural pheasant-rump yellow results in an attractive olive-yellow shade that retains much of the feather’s iridescence. The body is made from a rump feather twisted into a “noodle” and wrapped up the hook shank with a counter-wrapped, copper wire rib. The hackle is four turns of the same yellow dyed hackle. This is a rather sparse tie and probably comes closer to imitating a damselfly nymph than a dragonfly.
There’s a good story that goes with the fly’s name: Karl Haufler purchased some yellow-dyed pheasant-rump from the late Roy Patrick (founder of Seattle’s oldest fly shop). Tying up a few flies with it he took them to Pass Lake on Fidalgo Island. It was one of those days and Karl caught one fish after another while everybody else on the lake went fishless. Everyone who observed his success bombarded him with requests to beg borrow or steal one of his flies, so Karl came up with a simple barter-rate for his flies; hence the name.
I agree the Carey Special imitates several trout favorites including small fish. It is one of my favorite flies and a deffinite go-to fly for the lakes around here. Try tying them in a variety of colour combos… they key though is the phesant feathers, they have to be nice ones which can be hard to find at times.
From the book best flies for Idaho I quote" The carey speciel was created by Dr Lloyd Day and Col Carey of Quesnel, British Columbia around 1925. Tied with a peacock herl body and long pheasant rump feathers extending beyond the bend of the hook, the fly was originally intended to mimic an emerging caddis." It then goes on to say "However, the carey special suggests a plethora of other foood items, including damselfly and dragonfly nymphs.
Hope this helps