The Flavio imitates the emerging Small Western Green Drake (Drunella Flavilinea) - commonly referred to as simply "Flav". The Flav hatch is an important hatch in the western USA, generally taking place in the months of July and August.

Hook: Umpqua U203 #14, or any longshank curved hook
Thread: Benecchi 12/0, olive
Shuck: Antron, amber; Lemon woodduck barbs
Abdomen: Goose biot, dyed olive
Thorax: Argentinean hare, dyed olive
Wing: CDC, natural; polypropylene (or fine antron), grey
Legs: Whiting Brahma hen saddle, dyed dark olive (or brown partridge, dyed olive)
Head: Argentinean hare, dyed olive

Video here - please view in HD, if able:

Hans W