Blue Duns

This is the best Spring hatch after the Quill Gordons (Epeorus pleuralis) but before the Hendricksons (Ephemerella subvaria) in most parts of the East, although it can overlap with both. The Blue Quills are small mayflies (hook size 16-20) but they can hatch in incredible numbers at a time when eager trout are just beginning to look to the surface after a hungry winter.

This important Western species is one of the few mayflies outside the Ephemeridae family to possess large tusks on the front of its head. It is also one of the largest species of Paraleptophlebia.

P. bicornuta is often reinforced by simultaneous hatches of the more common Paraleptophlebia debilis. The two duns appear virtually identical to the naked eye, though bicornuta usually has an edge in size.

Paraleptophlebia bicornuta is by far the widest distributed tusked species, though there are others. Telling the tusked species apart is very difficult and even entomological texts are largely ambiguous on the characters that differentiate them. Distribution records are probably the most reliable way for anglers to know with any probability what they are looking at. Check out the Paraleptophlebia packii and Paraleptophlebia helena hatch pages for more distribution information.

Most anglers encounter these large mayflies every Spring in the East and Midwest. They are omnipresent in small portions, providing filler action in the days or hours between the prolific hatches of the early season Ephemerella flies.

See the main Leptophlebia page for details about their nymphs, hatching, and egg-laying behavior. This is by far the most important species of that genus.

This widespread species can produce memorable hatches where it is locally abundant, especially in the West where it also tends to run larger in size. It loves the margins as is typical of most Leptophlebiidae species but has a greater tolerance for current. They are often found even in riffles. This is the most important species in the West.

This species often emerges together with Paraleptophlebia strigula and Paraleptophlebia guttata, and the combined effect can be a good fishable hatch. The latter two are much less famous than mollis, but Knopp and Cormier say they are more reliable.