Damselnymphs are a part of very stillwater trout's diet - and an important one too, I think. The represent a fairly good bite and an imitation is an important part of any stillwater flybox.
The nymphs are present in most stillwaters, and prefer areas with a lot of flora and they are most often found in fairly shallow waters. Just like the mayflies, they exhibit what entomologists call incomplete metamorphosis, which means that they hatch from nymph directly to adult without a pupal-stage, which for instance caddis have. The nymphs are ferocious predators and feed on virtually anything smaller than themselves. They are easy to recognise from the rest of the species in the group Odonata. Long, slender abdomen with three distinct, broad tails. Three paris of long, fairly stout legs and a general length of 3/4 - 1 inch. Color is dependent on their specific habitat. In Scandinavia they hactch in late spring, early summer, but being predators they are active all year. Generally I fish them a tad larger in May and June, because the nymphs are fully grown at this time.
Paul is very particular about the way he ties this fly, so I must stress that this is my variation of Paul's fly :-).
The Arden Damsel
Hook: Any wetfly, here Varivas 2410 #10 (use a #12 for smaller versions).
Thread: Uni 8/0 - color to match.
Weight: 3mm tungsten bead.
Wingcase and legs: Pheasant tail fibers.
Body: Squirrel dubbing - but anything goes.
"Collar": Ice Dub - color to match.
Slide the bead on the hook and attach thread behind the bead. Run the thread down the shank to a point just before the hookpoint. Take off a clump of marabou and tie in where the thread is hanging.
Moisten the marabout tail to keep in under control and then take off a clump of pheasant tail fibers. Make sure you have enough to form a distinct thoraxcover/wingcase and legs. Measure the length - you'll need them long enough to fold over to form the wingcase and then back again to form the legs. I usually aim for about 3 times the length of the thorax. Dub the body with your preferred dubbing - I've used a mix of squirrel and SLF. Stop just short of the bead.
Dub out the small space you left between the bead and the body with the Ice Dub. That's give you a nice little collar of flash and keep the legs in place along the body. Using a piece of velco, tease out some of the flash and the fly is done!
From above..... I like the legs longish! If you tie an olive variant, it looks quite cool to use pheasant tail dyed light olive, or even chartreuse/lime green.
Paul told me he adapted John Goddard's Mayfly Nymph to imitate the damsel. It's a great fly that works really well. I tie it onto the leader with a loop knot to give it maximum freedom to move. The concentrated weight in front gives it a nice jigging action that keep the tail constantly moving, even on the drop!
Lars Chr. Bentsen (Viking Lars) (firstname.lastname@example.org) is a medieval archeologist flyfisherman - possibly the first. When not plundering, he either flyfishes the salt "concentrating at all times" or else investigates ruined castles, abbeys and burial mounds (this is true-life stuff). He is an FFF Certified (or at least certifiable) Master Flycasting Instructor and has a bag fetish. Lars lives with Pauline and their daughters, Anna and Elvira, and they try to live with him.