Fly of the Month: A Great Searching Pattern: The Stimulator

Moving on down the list of ETU Top Twelve Flies, we come to the Stimulator, an extremely popular fly pattern that is useful in a variety of situations.

It is recognized as the creation of Randall Kaufmann, a commercial tier who popularized it in the early 1980s. But many credit the original design to Jim Slattery, who first called it his Fluttering Stonefly and then later renamed it the Stimulator. It is also closely related to another fly, the Sofa Pillow, that Pat Barnes developed in the 1940s.

The Stimulator is commonly thought of as an attractor, or searching pattern, because it can resemble many things while imitating nothing in particular. And the fish go for it.

In large sizes and dressed with a salmon-orange body, it can be used to resemble the large black stonefly, also known as the giant salmon fly. In smaller sizes and colors, it is frequently chosen to suggest yellow stoneflies, small yellow sallies, little brown stoneflies and olive sallies. It can also work as a caddis fly. And if that isn't enough, you can tie it stoutly and even add rubber legs to fish it as a hopper, cicada or beetle.

In his book, Essential Trout Flies, Dave Hughes comments, “As a searching dressing, it is hard to beat the Yellow Stimulator. It looks like so many things trout eat that they're almost always glad to get one. Tie and carry it in sizes 8 through 12, and give it a prominent place in your dry-fly box, whether or not you fish stonefly hatches.” I'll have to say, Dave's advice has paid off for me. I have used it, or variations of it, on days when I have seen very few flies on the surface and absolutely no stoneflies. Nonetheless, drifting a Yellow Simulator down seam lines has succeeded in bringing up fish!

With all of its built-in flotation, the “Stimi” rides high and is easy to see. That's a huge plus for those of us who are visually challenged. It works great as an indicator in front of another dry, an emerger or even a nymph dropper.

The version illustrated here is a variant of the very popular classic Yellow Stimulator. It features light tan elk hair for tail and wing, a yellow body palmered with brown hackle and an orange thorax wrapped with grizzly hackle. Other commonly used body colors include orange, green, black and peacock. The dubbing I used was just what I happened to have on hand. So there's plenty of room to be creative with materials when tying this fly.

When I first tied the Stimulator, I found I had a tendency to crowd the eye of the hook by making the abdomen too long and not leaving enough room for the thorax and head. I also made the tail too long and too bushy. Measure your tail approximately to the hook gap and keep it on the sparse side. If you're a beginning tier, it will probably take some practice to get the proportions correct. But you'll soon be cranking out a lot of these reliable flies. And it will all pay off when ol' moss-back takes your Stimulator with a splashy rise!

Hook: Dai Riki 280 or TMC 200R, sizes 4-16
Thread: Hot Orange, 6/0 (I used Yellow Sheer 14/0 here)
Tail: Light elk hair
Abdomen: Yellow fur or synthetic dubbing
Thorax: Amber fur or synthetic dubbing (I used Orange Ice Dub here)
Body Hackle: Brown, sized to hook gap
Ribbing: Fine gold wire or tying thread
Wing: Light elk hair
Hackle: Grizzly, sized about the same or slightly larger than the body hackle
Tying Instructions:

Crimp or file away the hook barb and tie in your thread about one-third down the hook shank behind the eye. If you plan to use thread for the ribbing, leave a tag end about three inches long. Wrap your thread back to the bend, trapping the tag end under your wraps. You'll use that tag-end of thread as ribbing in a later step. If you intend to use wire for the ribbing as I did here, just tie in, trim the thread tag and wrap back to the bend.

Stack a small amount of elk hair and tie it in at the bend to form a tail roughly as long as the hook gap. Make the first several wraps of the tie-in fairly loosely to prevent the hair from flaring too much. While holding on to the butt ends of the hair, wrap your thread forward in spiral fashion over the hair, securing it to the shank. This creates an underbody for the abdomen. By using spiral thread wraps, you will preserve some of the hollow hair's loft to improve flotation. Wrap the thread forward to your initial tie-in point and trim the butt ends of the hair. Now wrap the thread back, again in spiral fashion, to the tie-in point of the tail. If you will be using a fine wire rib, tie in the wire at the base of the tail.


Apply the body dubbing to your thread and form a tapered abdomen, wrapping forward to the initial tie-in point. Avoid the temptation to advance any farther than the one-third point on the shank. If you advance too far forward with the abdomen, you'll likely wind up crowding the eye later.

Tie in your brown body hackle and palmer it back to the base of the tail. Tie off the hackle with your wire or thread ribbing, just like you would when tying an elk hair caddis. Wrap your ribbing forward, spiraling between the hackle wraps. Tie off the ribbing and trim the tag end. Carefully trim away the tag end of the hackle.


Stack a clump of elk hair for the wing. Tie in the wing at the one-third point, right in front of the abdomen. The wing should extend almost to the end of the tail. Again keep the first wraps a little loose to prevent the wing from flaring too much. Gradually increase thread tension and continue to make wraps through the flared butt ends of the hair. Trim off the butt ends of the hair, being careful to keep your thread out of the way.


The thorax of the fly will extend from the base of the wing forward to about one eye width behind the eye. Use thread wraps to make this section taper smoothly forward. That'll make it easier to apply dubbing and hackle to the thorax.

Return the thread to the base of the wing and tie in your grizzly hackle. Now dub the thorax forward, leaving room to form a head for the fly. Don't crowd the eye!


Wrap the grizzly hackle forward, leaving a little space between each wrap to allow the thorax dubbing to show through. Tie off the hackle, form a nice even head, and whip finish. Apply a drop of head cement, and you're done!


Photos and article by Tim Stechert