For the early black and brown stones I have two patterns that I fish. I tie them in sizes 12 to 20 to cover the many different species. The nymph pattern was I originally developed as an emerger. I got some laughs on that one as the stoneflies emerge on the banks. When stoneflies hatch there is a drift that ensues where they will drift in the surface for a considerable distance wiggling in the surface. If I choose to fish a nymph deep, I still use this pattern. Tails: Biots I like dk brown
Abdomen: Black or dk brown dubbing
Rib: Maxima mono
Thorax: Black Ostrich
Collar: Starling
The Dry that I fish is a pattern I have trusted for 33 years, I never miss this hatch. I fish to it every year. The first trout I caught on a dry fly was on this hatch with this pattern. The adults when laying their eggs flutter their wings and skate, any breeze will quickly blow all the adults back to the bank.
Body is tied like any ant, simple enough. Between them tied rearward forming a tail I tie two strands of strait black deer hair on each side forming a V shaped tail divided by the rear ball of dubbing. This tail forms the V shaped wake like the flutter naturals when skating and also provides a stable support to make the fly right correctly.
The wing is a pair of grizzly hackles wound catskill style. The wings in motion while fluttering are very well imitated by these hackles.
I have never found it necessary to imitate the adults with a downwing imitation. I can see this imitation easier as well.
I will try to post some pictures later.