Here are a couple variations of an olive emerger that I've been fishing when I've found fishing sipping small olives this fall. When tying small flies, you need to keep things very simple so that the fly's body doesn't become too bulky.
The main idea of the emerger is to keep the body of the fly in the surface film of the water with the wing above the surface so that the fly can be spotted and followed. When fishing small olives, your casts need to be dead on the feeding lane because fish don't move much for these small morsels. Your timing also needs to be right, so be patient and don't over-react when a fish takes a natural inches from your fly.
The CDC olive emerger uses CDC (oiler puffs) for the wing. The CDC allows the wing to be tied in with minimal bulk behind the wing so that the body remains slender. The CDC floats well but in my experience CDC is not very durable. After catching a fish or two, it's tough to get the fly to float again but I have caught fish on this fly "wet" on the swing, so even thought the fly gets beat up, it will still catch fish.
|CDC olive emerger|
TMC 100 #22/24
UTC 70D olive thread (body)
brown sparkle emerger yarn/zelon (tail)
dun CDC oiler puff wing
Another variation of this fly is to use light dun snowshoe rabbit fur for the wing. The snowshoe rabbit fur is much more durable than the CDC version but there are times when only the CDC emerger will take fish so it's good to have both on hand.
|Snowshoe rabbit olive emerger|
Same recipe as above
substitute snowshoe rabbit fur for the CDC
Tie some up and go catch a few on dries!