Isonichia Dun
Hook: Dry fly, Size #10 & 12, I use Tiemco TMC 100.
Thread: Brown.
Tail: Dun-colored hackle fibers, sparse clump approx. same length as body.
Body Dubbing: Rusty brown.
Parachute Post: White poly-yarn.
Hackle: Dun Hackle.
Well its fall time on the rivers here in CT. That means its olive time on the “Hous”. Two other things happen that fly fishers should be aware of. First, water temps are cooling and the trout are trying to put on some additional weight to get them through the upcoming winter months. Streamer fishermen can sometimes clean up while most others are fishing the little green olives. Secondly, and often overlooked, is a second less obvious mayfly hatch on the water. It’s the Isonichia Velma. (Although this insect’s heaviest time on the Hous is in the fall, they can be seen pretty much from late spring and early summer on the Farmington.)
The nymph is an extremely strong swimmer and actually crawls out of the water similar to a stone fly. Early on fall days I’ve had great success with an “iso” nymph. Last year I posted an iso nymph pattern on the “Fly of the Month”. The isonichia dun is one of the biggest mayflies on the water all year long. A pleasure to fish because it’s easy to see, trout really suck them in at times. As far as the pattern, it doesn’t get much simpler than this recipe. If you don’t have any of these dry flies in your box, try using an
adams parachute or royal trude of comparable size.