This fly is one of my favorite dry flies when fishing for big grayling and trout in September, October and November. I used it also in December on San river in Poland and I caught a lot of grayling and trout in the middle of the day when temperature rises at 2-3Celsius degrees. It's very easy to tie and highly recommended in this period when the sun warms the surface of the water.
Materials:
Hook: Maruto Dohitomi D04 size #18-20
Thread: UTC 70Denier
Body: UTC yellow and olive mixed
Tail: 3-4bars of Coq de Leon - Indio Claro
Wing:Khaki CDC one or two feathers.
cheers

Lucian