Great picture. Not sure I've seen it before. It IS what I am trying to imitate though.
The reason I tie the dark color only part ways up the abdomen is that if you add the trailing shuck (zelon material) you would have too much shucK in total - if you went all the way to the thorax.
Went back and tied one on a size 16 emerger hook. I prefer fishing the more "upright" versions on a std. dry fly hook, but these are representative of a slightly less emerged insect.