No, the wing is split by tying in a bunch of deer hair on top of the hook shank before winding the wing. The wing is deer hair tips and ginger dubbing in set into the thread, spun, and wound, guiding the deer hair back and up as you wind. I tied in the deer hair to split the wing quite long to make it easier to grab and pull forward. It gives the added advantage of using the butts of the hair for extra buoyancy, if you don't pull too tight. The dubbing is only there to make sure the hair is secure in the thread.

The technique is the same as Marc Petitjean uses in his dun patterns, just different materials.

Cheers,
A.