The Yellow Quill is the albertae species of the Epeorus genus. It usually merges in the late afternoon. Spinner falls can occur from mid-afternoon until evening. The female dun is also called the “Pink Lady”. This is a Western species that is found in moderate to fast water. This mayfly is also called the Slate Brown Dun. It is often confused with the Slate Dun which is very similar. The most important thing about this mayfly is the fact that it often hatches when no other mayflies are hatching.