The pattern shown is the video tying of the yellow May Dun which is already on the site in step by step photographs. I was asked to put this video together to make it more clear as to how the wings were created.
 

The materials need are detailed below.

Hook:   size 14 dry fly

Silk:  light yellow or primrose 14/0 to 8/0

Tail:  Hackle fibres from a cock hackle dyed yellow sunburst.

Body: Number 47 fly-rite or any dry fly dubbing coloured bright yellow

Wing:  Mallard silver flank feather dyed yellow

Hackle: Sunburst yellow cock hackle.