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

Dark Brown Spinners

Like most common names, "Dark Brown Spinner" can refer to more than one taxon. They're previewed below, along with 6 specimens. For more detail click through to the scientific names.

Mayfly Genus Paraleptophlebia

These are very rarely called Dark Brown Spinners.
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 the two region's 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:
Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly NymphParaleptophlebia (Blue Quills and Mahogany Duns) Mayfly Nymph View 6 Pictures
Collected February 7, 2004 from in
Added to Troutnut.com by on January 25, 2006
Male Paraleptophlebia adoptiva (Blue Quill) Mayfly DunMale Paraleptophlebia adoptiva (Blue Quill) Mayfly Dun View 14 Pictures
Collected April 30, 2007 from in
Added to Troutnut.com by on May 3, 2007
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 in
Added to Troutnut.com by on October 4, 2006
Male Paraleptophlebia heteronea (Blue Quill) Mayfly AdultMale Paraleptophlebia heteronea (Blue Quill) Mayfly Adult View 1 Pictures
Collected May 16, 2012 from in
Added to Troutnut.com by on May 18, 2012

Mayfly Species Tricorythodes allectus

These are very rarely called Dark Brown Spinners.

Mayfly Species Drunella coloradensis

These are very rarely called Dark Brown Spinners.
This species is very similar to Drunella flavilinea. In areas where their ranges overlap, they can sometimes be found in the same streams. Allen and Edmunds (1962) say that Drunella coloradensis tends to favor colder water than Drunella flavilinea and that it may emerge as much as a month later.

Mayfly Species Ameletus cooki

These are very rarely called Dark Brown Spinners.

Mayfly Species Teloganopsis deficiens

These are very rarely called Dark Brown Spinners.
Anglers in western Wisconsin, where these little flies hatch in good numbers on summer rivers, have termed them "Darth Vaders" because of the very dark color of their wings.

Until recently, this species was known as Serratella deficiens.
Teloganopsis deficiens (Little Black Quill) Mayfly NymphTeloganopsis deficiens (Little Black Quill) Mayfly Nymph View 6 PicturesThis nymph has tiny, barely detectable tubercles (
A few (not all) of the abdominal tubercles on this Ephemerella needhami nymph are circled.  They are especially large in this species.
A few (not all) of the abdominal tubercles on this Ephemerella needhami nymph are circled. They are especially large in this species.
Tubercle: Various peculiar little bumps or projections on an insect. Their character is important for the identification of many kinds of insects, such as the nymphs of Ephemerellidae mayflies.
)
on its abdominal segments, and I could not find the maxillary palpi. I have tentatively guessed that it is Serratella deficiens.
Collected June 9, 2005 from in
Added to Troutnut.com by on May 26, 2006

Mayfly Species Diphetor hageni

These are very rarely called Dark Brown Spinners.
This is one of the most important species of the Baetidae family. Previously known as Baetis parvus in the West and its synonym (Synonym: A former name of a taxon, usually a species. Entomologists frequently discover that two insects originally described as different species are one in the same, and they drop one of the names. The dropped name is said to be a synonym of the remaining name. These changes take a while to trickle into the common knowledge of anglers; for example, Baetis vagans is now a synonym of Baetis tricaudatus.) Baetis devinctus in the East, it is distributed across the country but most of its fame comes from excellent hatches in the West. Prior to all the species being combined with Baetis tricaudatus, most angling literature considered it the most populous and widespread western species of the Baetidae family.

Dorsal (Dorsal: Top.) abdominal markings on the nymphs used to differentiate the species in these older works have since proved unreliable. The easiest way to tell them apart from B. tricaudatus is their lack of gills on the first abdominal segment. Telling adults apart is equally tough. Duns of D. hageni are typically a little smaller, but their bodies can also be olive, brownish olive and even two toned with thoraxes a shade of brown or tan with paler olivacious abdomens.

Diphetor hageni has two former names used in angling literature, Baetis parvus in the West and Baetis divinctus in the East.

Mayfly Species Tricorythodes minutus

These are very rarely called Dark Brown Spinners.
Top 10 Fly Hatches
Top Gift Shop Designs
Top Insect Specimens
Miscellaneous Sites