If published hatch charts are to believed, there is a decent chance that we will catch part of the Green Drake emergence while we're in Roscoe this year. And also based on what I've been reading, trout reportedly prefer to eat the nymphal stage of the fly as opposed to the duns, even when an active hatch is in progress. For these reasons, I thought it might be a good idea to have a nymph pattern on hand. After looking at quite a few photos of actual green drake nymphs and various patterns that folks have devised to imitate them, I came up with the following:
Hook: Daiichi 1550, Size #10
Thread: Uni-Thread 8/0, black
Tail: Barbs from small feathers found near the base of a complete pheasant tail clump
Abdomen: Ostrich herl dyed olive
Wing case: Slip from black band on white-tipped turkey tail feather
Thorax: Natural hare's poll in dropped loop
Legs: Chinese partridge back (lighter shades than on Hun)
NOTE: This post was edited in 2017 to replace the photo lost to Photobucket. It may be of interest to know that I have fished this pattern with considerable success in the intervening years, even when the Green Drakes were not in evidence.

Some of the same morons who throw their trash around in National parks also vote. That alone would explain the state of American politics. ~ John Gierach, "Still Life with Brook Trout"