Description I have used this pattern, religiously, since my trip to New Zealand in 1991. It has been one of the most productive (and consistent) nymph patterns I have ever used; trout and steelies love it. Hetero-genius nymph was designed as both an attractor and an imitator; the best of both worlds. IT'S HETERO-GENIUS! Best in size 12 to 18. Hint: Get it down to the fishes level and bump it, sporadically.