This Corixa pattern, originated by Paul Slaney, will do the damage on lakes around the world - be it fished as a single pattern, or in a team of flies where the rules allow multi-fly rigs.

Hook: Tiemco 2499SP #14 (or equivalent scud hook)
Thread: Gudebrod 8/0, white
Flash 1: Krystal Flash, black
Flash 2: Mylar, silver #14
Underbody: Tying thread
Body: Hare's ear, pale
Hackle: Starling

Video here - please view in HD, if able:

Hans W