Hook:

18 - 22 Tiemco 2487 or 2488 (straight eye)

Thread:

8/0 Uni-Thread Olive, Grey or Rust

Wing Post:

1/16" dia. foam post

Tail:

Mayfly Brown straight zelon

Body:

BWO Olive Superfine, Beaver or Zelon Dubbing 

Hackle:

Light Dun

This is another great fly in the BWO arsenal.  Similar to the Klinkenhamer style of low riding emerger, this gives the trout something different to look at - a little spice in their life!  Experiment with different dubbing colors to better match your particular flavor of emerging Olive mayfly.