Here's a cripple/emerger pattern that worked very well for olives last spring, and for sulphurs for a while:
Parachute emerger for spring olives in PA. In fall smaller sizes may be necessary. This fly also works very well for sulphurs, PMD’s etc in the right sizes and colors, of course:
Hook: Size 18 Gamakatsu C15-BV, Varivas old # 999 (now #2200 if you know someone in Japan), Kamasan scud hook, or any scud hook would probably work. The Gamakatsu barbless hooks hold well, have a great bend, and are becoming my favorites, though I like the Varivas hook a lot too. Check out the Gamakatsu hook on the web.
Thread: olive 8/0, 10/0 or gel spun. The smallest thread that is strong enough is best for finishing the fly.
Abdomen: dark biot. I have started with dark brown with a reddish brown center and had become somewhat superstitious about it, having caught some very difficult fish with this color, but recently tied some with dark olive biots that have worked very well. I do believe the biot needs to be dark and to contrast the thorax when the fly is wet.
Thorax Dubbing: Caucci spectrumized for baetis, or any light to medium olive rabbit fur dubbing should work,
Hackle: whiting medium dun or dark dun, size 20,
Post: White, Black, or Orange Poly Yarn or other visible material. Could use grey Hi viz, but I like to see this fly.
Tail, short antron or zelon fibers to match the biot. I sometimes tie in a bit of olive dyed mallard too.
Tie in thread and wrap down the bend to almost where the biot will start, creating a tapered underbody like a nymph with the thread on the bend of the hook where the biot will be wrapped. See fly for proportions. If just using Zelon or antron, tie in the tail there wrapping across the center of the very sparse fiber bundle (which will end up doubled), then bring the upper fibers to point down with the others and tightly overwrap the tie in and down a few wraps to bind the shuck/tail in forever. (If I use mallard, I tie it in first, as with any fiber tail, then add the zelon). Moisten the biot and tie it in. Coat lower thread wraps lightly with polyurethane glue (Gorilla glue). Wrap the biot up squeezing the glue along, and wipe any excess after you tie off the biot. Ideally there will be no excess if you get the right amount to start. I sometimes use black marker to suggest the wing pads, and a drop of flexament on top to secure the thread wraps and suggest a wingcase. Advance the thread to a midpoint of the remaining shank and tie in the post. I use Gary Borger's stirrup method, slipping the poly yarn or high viz under the shank and pulling both ends up to create a post that can't pull out. A few X wraps under the hook to secure the post, a tiny drop of super glue at the base and some more quick X wraps and posting wraps at the base of the post and up a bit, and the post is ready and won't slip around later. Then I strip some barbs from a dun hackle, tie in it in along the shank just behind the eye, and then wrap the stem up the post to to reinforce and further stiffen the post. Next I dub the thorax, ending up with the thread wrapped 1 half turn clockwise around the post and hanging on the side of the fly towards me between the post and the eye. Next, wrap the hackle clockwise around the post, 4-5 wraps, with each wrap under the former one. When I’m done, I trap the hackle stem with the thread under the wraps, and with the hackle tip pulled straight down by the hackle pliers, tie off (I wrap clockwise and whip finish using a whip finish tool under the hackle on the post with a few wraps (usually 3). A ultra-mini drop of gorilla glue on the thread of the final whip finish loop that is going to be pulled into the knot is pulled in from below, avoiding the hackle, to lock it all in permanently. Trim the hackle tip and the thread, let the gorilla glue dry, and you’re ready to fish.
"He spread them a yard and a half. 'And every one that got away is this big.'"
--Fred Chappell