This tasty little nugget is Eric Stroup's Snowshoe Trico Spinner. Eric originally tied it on video for a program we produced along with the world renowned Charlie Meck. The 2 DVD set, called Practical Patterns, was released in 2006 and was shot in standard definition. The information is still valid and valuable but I thought an HD update of tying this particular pattern was warranted.
The pattern is tied on a size 20 #125 Dai-Riki Emerger hook, regardless of how small you want the final fly to be. The real advantage of using this style hook in this size, it's the hook on the left, versus say a size 24 dry fly hook, on the right, is the increased hook gap which generally makes it easier to hook fish.
For thread, I'm going to use black UTC 70 Denier. Start your thread on the hook shank just behind the eye and take wraps rearward to the barb. Then wrap about half way back up the shank.
The only other material needed for this fly is hair from the foot of a Snowshoe rabbit. Snip a small clump free from the foot. I like to pull out the fluffy underfur as well as remove the courser, longer guard hairs but this really isn't necessary. Once you've got a good looking clump of hair, center it on the hook shank above your tying thread. Take a couple wraps to get it secured to the shank and then carefully make cross wraps to get the hair oriented perpendicular to the hook shank. Tricos have beefy little thoraxes so taking multiple cross wraps is just fine.
With that done, pull the wings back and take a few wraps of tying thread behind the eye. You can then, once again, pull the hair back and do a 5 or 6 turn whip finish to secure the thread. Then, snip or cut your tying thread free.
There are several different ways to cut the wings to length. I like to pull them both up at once from the bottom and give them a rough snip to length. If they're too long I simply pull them up again and give them a little trim.
And that's really it. You could add tails if you like but most of the time it's not necessary. To adjust the size of the fly, shorten or lengthen the thread body and then snip the wings accordingly. So the next time you're on the stream during the early morning in say July through September, and you see a cloud of insects that looks something like this, and some of those bugs start dropping out and landing on the water's surface and the trout are feeding almost rhythmically, like this, tie on one of Eric's ultra-simple Trico Spinners and give it a shot.