I have one box devoted to nothing but zebra midges in Black, Red, orange, gray, olive and brown. All with bead heads. So of them I have add a flouro-fiber wing case (those are in a size 14 and are very effective in the slow or still water).

When fishing these I will fish them under a strike indicator about 10-12" under the surface to emulate an emerging little fella. Put a tungsten bead on that fly and it drops like a rock and you get good drift. Last December on the Lower Illinois River, I fished on zebra for 4 hours and landed thirty (I swear) 'bows. It was one of those days.

Recently I have started tying a version of a mercury midge in size 20, 22. Using a glass bead and a slimmer profile.