Patterns based on the extended body idea are old. But very often the chenille you’ll find at the fly shops are thick and chunky. Work great for the larger variants, but for the small mayflies in the late hatches, those polychenilles are simply to fat. A couple of years ago I came across a great micro poly chenille that was thin enough to compare with the diameter of the thin Ignita abdomen. If you take a close look at the picture, you’ll see that the diameter of the Micro Polychenille in fact is just marginally fatter than the hook shank.
This pattern is fun to fish with, because the fly isn’t very pretty and the amount of bling and attractors is limited.
In my view the most important attractor on this orange killer is the body profile.