Harrop's CDC Transitional Midge is a simple but effective midge emerger pattern originated by Rene Harrop for western waters but that works like a charm on southern freestone and tailwater trout flows. If you have trouble seeing them on the water, tie on a larger dry first, then tie about 20 inches of tippet to the bend of that fly to which you then tie this fine pattern.
Hook: TMC 100 #20-24
Thread: 6/0 Olive Danville
Tail/Shuck: Grizzly hackle tip
Overbody/Legs/Head: Natural CDC puff
Body: Australian opossum - natural