Used all over the world this is one great fly. Invented by Sawyer on the river Itchen in England (I fished with John Goddard the very part he is supposed to have invented this fly). This is the go to fly in most fly boxes and you just cannot be without it. is popular as an unweighted nymph as it can be mistaken for a chironomidae but mostly it is taken in NZ as a mayfly larvae and is often fished with a beadhead in fast running water.
Tip - Guides Secret: Fish a size 14 on a dropper 12 inches behind a larger Bead head nymph ...deadly.