Not a typo (if you want to see a Stimulator, check out Charlie Craven's; best one I've ever come across); the Simulator is another Bugger variation, similar to the Leib Bug without the front wings, and Polly Rosborough's Non-descript Nymph (Oregon's obviously a Fertile Crescent of flytying). Tied in-the-round style, there is no right side up or upside down. It's the kind of fly you can fish amongst the rocks (where the stoneflies live and the trout know it) and not care when you get snagged on occasion; quick and easy to tie - much easier than Kaufmann's Stonefly (I weep when I lose them).
hook - Mustad 79580 #6
thread - Danville 6/0 black
underbody - non-tox wire .025
tail - biots black
rib - copper wire x-fine
body - dubbing mix rabbit/angora (black, brown, red, orange)
hackle - black saddle
Part 1
mash barb, wrap shank with non-tox
start thread, wrap underbody; taper front and back
even up biots, curving away from each other
measure for length (hook gap), tie in and smooth butts
tie in rib
dubbing