This is a big beef. It is only a emerger/adult pattern which is blown up.
From experience this pattern works both as a fish finder and under caddis hatches.
Try this on once you are in the river
Hook : Mustad 10549npbr #6
Tying Thread : Semperfli Classic Waxed thread 8/0, Black
Tag : Semperfli Fluoro Brite, Green
Ribbing : Crystal Flash Fibers
Body : Alpacka Dubbing, Brown Olive
Hackle : Cdc, Dark Brown (in a loop)
A relatively straight forward fly to tie. As tag you can also use dubbing if you want that. And even change the color on both the tag and the body, to imitate the caddis in your river or lake.