Here you go folks, the Chimarra caddis larva pattern. I tied a heck of a lot of these the last three days at the show, as part of my presentation included this February/March "must have" subsurface pattern. Unfortunately, none of the fly shops that were at the show brought the essential ingredient - yellow flexx floss.
Hook: #18 Scud
Underbody: 6/0 Danville orange thread
Overbody: Yellow flexx floss
Head: 6/0 Danville tobacco brown thread
Tie some up and fish them behind a heavier nymph.