The Elk Hair hopper is very effective when trout are taking hatching midge. It can be fished on a floating line and left static or slowly twitched across the surface. A number of takes have also been taken subsurface using a variety of retrieve techniques from very slow to very fast. This elk hair version can also be used when sedges or grasshoppers are on the water.
I found last season that this fly pattern was really productive as a dry fly when mayfly were on the water.