Hook: 3X-long curved-shank hook such as the Daiichi 1270, your choice of sizes.
Thread: Size 8/0 (70 denier) or 6/0 (140 denier), color to match the natural insect.
Tail: Natural elk or deer body hair.
Underbody: The butt ends of the tail fibers.
Abdomen: Dry-fly dubbing, color to match the natural.
Body hackle: Dry-fly neck or saddle hackIe. The length of the fibers should be no longer than the width of the hook gap.
Rib: The tag end of the tying thread, fine tinsel, or your choice of flash material.
Wing: Natural elk or deer body hair.
Thorax: Dry-fly dubbing, color to contrast with the abdomen.
Thorax hackle: Dry-fly neck hackle. The fibers should be 1 1/2 to 2 times the width of the hook gap.

Stimulator Variations
Tail: Any hollow hair (such as deer or elk hair), calftail, squirrel tail, synthetic fibers, or Krystal Flash.
Body: Dry-fly dubbing, polypropylene yam, closed-cell sheet foam sheeting, coarse dubbing (such as a seal's fur substitute), floss, or peacock herl.
Wing: Krystal Flash and Shimazaki Wing material to create the Seducer, synthetic fibers or any hollow hair, calftail, squirrel tail, or white calftail over the elk for greater visibility in low-light conditions.
Thorax: Dry-fly dubbing or spun hollow hair such as deer hair.
Legs: Straight or knotted rubber legs or knotted pheasant tail fibers.
Head: Spun deer hair with or without hackle, peacock herl or ostrich herl, or hollow hair tied on and pulled back to form-a bullet-shaped head.

The Stimulator was originally tied to imitate western stoneflies. Today, the Stimulator is also used to imitate caddisflies, grasshoppers, crickets, cicadas, and beetles. By changing hook sizes and material colors, you can tie Stimulators to imitate a wide variety of insects. (Fly Tyer, Winter 2007)