There are many species in this genus of mayflies, and some of them produce excellent hatches. Commonly known as Blue Quills or Mahogany Duns, they include some of the first mayflies to hatch in the Spring and some of the last to finish in the Fall.
» Genus Paraleptophlebia (Blue Quills and Mahogany Duns)
20 species aren't included.
In the East and Midwest, their small size (16 to 20, but mostly 18's) makes them difficult to match with old techniques. In the 1950s Ernest Schwiebert wrote in Matching the Hatch:
"The Paraleptophlebia hatches are the seasonal Waterloo of most anglers, for without fine tippets and tiny flies an empty basket is assured."
Fortunately, modern anglers with experience fishing hatches of tiny Baetis and Tricorythodes mayflies are better prepared for eastern Paraleptophlebia. It's hard to make sense of so many species, but only one is very important and others can be considered in groups because they often hatch together:
In the West, it is a different story. For starters the species run much larger and can be imitated with flies as large as size 12, often size 14, and rarely smaller than 16. Another difference is the West has species with tusks! Many anglers upon first seeing them think they are immature burrowing nymphs of the species Ephemera simulans aka Brown Drake. With their large tusks, feathery gills, and slender uniform build, it's an easy mistake to make. Using groups again:
Hatching BehaviorThough usually noted for migrating to the shallows to hatch, most species at times emerge in classic mayfly style on the surface and ride the water for a while before flying away. This is exacerbated by the inclement weather they often hatch in. Floating nymph patterns and emergers are very effective at these times. The hatch may last for a few hours each day.
George Edmunds in Mayflies of North and Central America documented that Paraleptophlebia mayflies have been observed to emerge by crawling out onto shore when the water is high in the Spring, but since he gives no further details about which species do this it is reasonable to assume it's generic. Knopp and Cormier note in Mayflies: An Angler's Study of Trout Water Ephemeroptera the same behavior.Spinner Behavior
Time Of Day: Weather dependantAccording to Edmunds, the females will mate more than once and often proceed to shoreline foliage when finished with ovipositing as opposed to dying spent (Spent: The wing position of many aquatic insects when they fall on the water after mating. The wings of both sides lay flat on the water. The word may be used to describe insects with their wings in that position, as well as the position itself.) on the water. The males start the swarms first, often well before. They are often observed along the shoreline dipping from six to two feet and rising again. On occasion, many males for unknown reasons drop to the water at this time and become trapped in the meniscus. When the females finally arrive, they join them quickly at the top, copulate during the four foot fall, and just as quickly make short dives to either dip their abdomens into the water or land on the water to lay their eggs. Then it's up and back at it until they're finished. Edmunds reports that they will repeat this cycle as many as three times before they occasionally die spent (Spent: The wing position of many aquatic insects when they fall on the water after mating. The wings of both sides lay flat on the water. The word may be used to describe insects with their wings in that position, as well as the position itself.) on the water or more often head back to the bushes. This is good information for the angler to note.Nymph Biology
Habitat: Soft margins
Current Speed: Moderate to fastAlthough classified as crawlers, Paraleptophlebia nymphs look more like little burrowers (especially the tusked variety) and swim very well. They are generally tolerant of faster water than Leptophlebia and inhabit pockets in riffles as well as moderate runs.
Substrate: Sand, gravel, detritus (Detritus: Small, loose pieces of decaying organic matter underwater.)