Blog & Latest Updates
Fly Fishing Articles
Insects by Common Name

Trout Streams & Rivers
Trout Pictures
Underwater Pictures

Desktop Backgrounds
Stream & Bug Videos
Image Use Pricing

**Mayfly Genus Paraleptophlebia (Blue Quills and Mahogany Duns)**

Mayflies

Caddisflies

Stoneflies

Taxonomic Navigation -?-

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Insecta (Insects)

» Order Ephemeroptera (Mayflies)

» Family Leptophlebiidae (Blue Quills and Mahogany Duns)

» Genus Paraleptophlebia (Blue Quills and Mahogany Duns)

Species in Paraleptophlebia
Paraleptophlebia bicornutaMahogany Dun	0	0
Paraleptophlebia debilisMahogany Dun	0	0
Paraleptophlebia falcula	0	0
Paraleptophlebia gregalisBlue Quill	0	0
Paraleptophlebia guttataBlue Quill	0	0
Paraleptophlebia helenaMahogany Dun	0	0
Paraleptophlebia packiiMahogany Dun	0	0
Paraleptophlebia praepeditaMahogany Dun	0	0
Paraleptophlebia sculleni	0	0
Paraleptophlebia strigulaBlue Quill	0	0
Paraleptophlebia vaciva	0	0
Paraleptophlebia zayante	0	0

20 species aren't included.

Common Names

Match	Common Name
	Blue Quills and Mahogany Duns
	Paraleps
	Blue Quills
	Mahogany Duns
	Slate-Winged Mahogany Duns
	Dark Blue Quills
	Dark Brown Spinners
	Blue-Winged Duns
	Jenny Spinners

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:

Paraleptophlebia adoptiva is by far the most important species of this genus in the two regions and is an early Spring emerger.

Paraleptophlebia mollis, Paraleptophlebia guttata, and Paraleptophlebia strigula complement each other in late spring and early summer.

Paraleptophlebia debilis and Paraleptophlebia praepedita occur together in the fall.

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:

The most important species is Paraleptophlebia debilis. This large (for the genus) Fall emerger can be found throughout the region. It is often accompanied by one of the slightly larger tusked species. Depending on locale, this can be Paraleptophlebia bicornuta (the most common), Paraleptophlebia packii or Paraleptophlebia helena. Check out their hatch pages for distribution information.

Spring is the season for the smaller Paraleptophlebia heteronea throughout most of the region with Paraleptophlebia gregalis filling this niche in California and parts of Oregon.

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.

Jargon Defined:

Abdomens: The rear and usually the longest (ten-segmented in mayflies) portion of an insect's body, to which the tails are attached.

Detritus: Small, loose pieces of decaying organic matter underwater.

Duns: Mayflies have two adult stages. They first emerge from the water as duns (scientifically known as the subimago stage). They then molt into the spinner (imago) stage, in which they mate and die. Sometimes the word "dun" is confusingly used to refer to a brownish gray color in fly tying materials.

Nymphs: The juvenile, underwater stages of mayflies, stoneflies, dragonflies, and damselflies and other aquatic insects whose juvenile stages are covered by hard exoskeletons. The word can also refer to the fishing flies which imitate these creatures, in which case it is used as a blanket term for flies imitating any underwater stage of an invertebrate (except for crayfish and leeches).

Ovipositing: To lay eggs.

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.

Useful References:

Arbona, Fred Jr. 1989. Mayflies, the Angler, and the Trout. Nick Lyons Books.

Caucci, Al and Nastasi, Bob. 2004. Hatches II. The Lyons Press.

Fauceglia, Ted. 2005. Mayflies . Stackpole Books.

Knopp, Malcolm and Robert Cormier. 1997. Mayflies: An Angler's Study of Trout Water Ephemeroptera . The Lyons Press.

Leonard, Justin W. and Fannie A. Leonard. 1962. Mayflies of Michigan Trout Streams. Cranbrook Institute of Science.

Schwiebert, Ernest G. 1955. Matching the Hatch. MacMillan Publishing Company.

Swisher, Doug and Carl Richards. 2000. Selective Trout. The Lyons Press.