From the designer, Devin Olsen:

Stripped peacock quills make perfect segmented bodies which imitate the natural color patterns on mayflies. The only issue is that they are fragile and often shred after a few fish. However, when covered in resin for a perdigon style body they make the perfect material for representing small mayfly nymphs. The Quilldigon features this naturally effective material combined with a turn of pearl flash at the rear to set it apart from natural mayfly nymphs in the drift. It has become one of my most reliable patterns anywhere that I fish. Small mayflies are nearly ubiquitous in trout streams around the globe and the effectiveness of this fly follows that pattern.