Fly Fishing for Trout Home
User Password
or register.
Scientific name search:

Mayfly Genus Paraleptophlebia (Blue Quills and Mahogany Duns)

Taxonomic Navigation -?-
» Genus Paraleptophlebia (Blue Quills and Mahogany Duns)
Species in ParaleptophlebiaNumber of SpecimensNumber of Pictures
Paraleptophlebia bicornutaMahogany Dun00
Paraleptophlebia debilisMahogany Dun00
Paraleptophlebia falcula00
Paraleptophlebia gregalisBlue Quill00
Paraleptophlebia guttataBlue Quill00
Paraleptophlebia helenaMahogany Dun00
Paraleptophlebia packiiMahogany Dun00
Paraleptophlebia praepeditaMahogany Dun00
Paraleptophlebia sculleni00
Paraleptophlebia strigulaBlue Quill00
Paraleptophlebia vaciva00
Paraleptophlebia zayante00

20 species aren't included.
Common Names
Pictures Below
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.

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 Behavior

Though 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 dependant

Habitat: Soft margins
According 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

Current Speed: Moderate to fast

Substrate: Sand, gravel, detritus (Detritus: Small, loose pieces of decaying organic matter underwater.)

Although 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.

Pictures of 30 Mayfly Specimens in the Genus Paraleptophlebia:

Specimen Page:1234
Male Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly SpinnerMale Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly Spinner View 15 PicturesI wasn't actually fishing the river where I caught this one. I was just scouting, didn't like the look of the water, and as I was walking back to the car this little dun landed on my vest. Why can't they all be so easy to collect?
Collected September 8, 2006 from the East Branch of the Delaware River in New York
Added to by Troutnut on October 4, 2006
Male Paraleptophlebia sculleni Mayfly SpinnerMale Paraleptophlebia sculleni  Mayfly Spinner View 13 PicturesThis specimen (and a few others I collected but didn't photograph) appear to represent the first finding of Paraleptophlebia sculleni outside the Oregon Cascades, although it is not a monumental leap from there to the Washington Cascades. The key characteristics are fairly clear.
Collected July 25, 2019 from Mystery Creek #249 in Washington
Added to by Troutnut on July 26, 2019
Specimen Page:1234

Recent Discussions of Paraleptophlebia

Western Paraleptophlebia 17 Replies »
Posted by Entoman on Feb 4, 2012
Last reply on Feb 7, 2012 by Entoman
Paul wrote in another topic:

Yes, the Paraleps can come about the same time as the tricaudatus, but don't start as early I think. And I think they were a mid-morning deal where tricaudatus has more of an afternoon peak. (Here in the rockies we're not supoosed to don't have the early P adoptiva, although last spring I found a single youngish nymph that my key would only take it to adoptiva -by gills if I remember right. Wish I'd pickled it and had it properly ID'd.

Anyway, back east I found the Paraleps emerged from slower currents and siltier substrates -often along stream edges. Whereas tricaudatus spilled out of the riffles. They could mix of course in certain places, but one could find one predominant if you wanted to (and I did bc I wanted to know each better), by focusing on key habitat.

Fly patterns could be identical really, although I had my own, esp for the nymphs. In fact, I'm still using some P adoptiva mimic parachutes (more a dun gray) during Baetis activity.

I largely agree, though they seem to be more tolerant of current than most genera of leptophlebiids. I have sampled them from riffles. In my experience (with an admitted western bias), they are far more important in the Fall. If an angler is lucky enough to be in place (and aware of them) when they are schooled up in preparation for hatching, some memorable nymphing can take place! :)

P. adoptiva is an eastern species. By far the most important species in the West is P. debilis, though they can be found mixed with others, particularly the unusual tusk bearing species bicornuta and in some locales packii. Anglers that occasionally come across these tuskers often confuse them with the immature burrowing ephemerids they resemble. Many anglers use their standard nymphs and do just fine with them. The PT is a popular pattern. Sometimes, a nymph that more accurately suggests their silhouette is the ticket. Because of their build and very obvious gills, they look more like a small long-tailed burrower than they do the typical baetid or ephemerellid, and it is good for the angler to keep this in mind.

Most duns and spinners are typically a rich brown, hence the name "Mahogany Dun." They can run the gamut from gray to almost black though, depending on the location. The slender bodies and coloration of the duns lead to them often being mistaken for baetids, but the oval vertically held hind wings and three tails make them easy to distinguish from that family. Check out this link to the hatch page for a look at the natural dun.

Below are a couple of patterns I find very useful when this critter is about.

Mahogany Dun Nymph #16

(User-posted images are only viewable in the forum section.)

(User-posted images are only viewable in the forum section.)

Mahogany Paradun #16

(User-posted images are only viewable in the forum section.)

ReplyParalep Hatching Behavior 9 Replies »
Posted by Shawnny3 on Apr 6, 2009
Last reply on Apr 30, 2009 by Taxon
I can't remember where I read or heard these things (might have been on this site), but I want to make sure my vague recollections are not totally false. When Paraleptophlebia are mating, do they make exaggerated dives in clouds above the stream? If so, do they often end up in the water at these times or do they fall as spinners much later? Finally, when they emerge, do they do so at the stream bottom and then swim to the surface as duns?

Thanks for any help,

Your Thoughts On Paraleptophlebia:

You must log in at the top of the page to post. If you haven't registered yet, it's this easy:

Username:          Email:

Password:    Confirm Password:

I am at least 13 years old and agree to the rules.
Top 10 Fly Hatches
Top Gift Shop Designs
Top Insect Specimens
Miscellaneous Sites