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Pale Sulphur Duns

Like most common names, "Pale Sulphur Dun" can refer to more than one taxon. They're previewed below, along with 10 specimens. For more detail click through to the scientific names.

Mayfly Species Maccaffertium ithaca

These are sometimes called Pale Sulphur Duns.
Maccaffertium ithaca (Light Cahill) Mayfly NymphMaccaffertium ithaca (Light Cahill) Mayfly Nymph View 9 PicturesThis specimen seems to be of the same species as a dun I photographed which emerged from another nymph in the same sample.
Collected May 29, 2007 from in
Added to Troutnut.com by on June 4, 2007
Female Maccaffertium ithaca (Light Cahill) Mayfly DunFemale Maccaffertium ithaca (Light Cahill) Mayfly Dun View 10 PicturesThis female looks very much like a male I collected a few hundred miles away a few days later, so I'm guessing it's the same species, which I believe is Maccaffertium mediopunctatum.
Collected May 23, 2007 from in
Added to Troutnut.com by on June 4, 2007

Mayfly Species Ephemerella dorothea dorothea

These are very rarely called Pale Sulphur Duns.
Ephemerella dorothea consists of two subspecies (Subspecies: Entomologists sometimes further divide a species into distinct groups called subspecies, which have two lower-case words on the end of their scientific name instead of one. The latter is the sub-species name. For example, Maccaffertium mexicanum mexicanum and Maccaffertium mexicanum integrum are two different subspecies of Maccaffertium mexicanum.), which both produce excellent action. Ephemerella dorothea dorothea is a small species of Sulphur in the East, and Ephemerella dorothea infrequens (formerly Ephemerella infrequens) is one of the two main Pale Morning Dun hatches of the West. The remainder of this page focuses on the dorothea dorothea subspecies (Subspecies: Entomologists sometimes further divide a species into distinct groups called subspecies, which have two lower-case words on the end of their scientific name instead of one. The latter is the sub-species name. For example, Maccaffertium mexicanum mexicanum and Maccaffertium mexicanum integrum are two different subspecies of Maccaffertium mexicanum.), and Ephemerella dorothea infrequens is discussed separately on its own page.

This is one of the most challenging mayfly hatches on Eastern waters. On many streams, it follows or overlaps hatches of the larger, lingering Ephemerella invaria.
Ephemerella dorothea dorothea (Pale Evening Dun) Mayfly NymphEphemerella dorothea dorothea (Pale Evening Dun) Mayfly Nymph View 6 PicturesI keyed this nymph carefully under a microscope to check that it's Ephemerella dorothea.
Collected May 29, 2007 from in
Added to Troutnut.com by on June 4, 2007

Mayfly Species Ephemera varia

These are very rarely called Pale Sulphur Duns.
This is an excellent hatch of a different character than its Ephemera brethren. Rather than emerging in a flurry of activity within a week, the Ephemera varia flies may last for more than a month in a single place.
Ephemera varia (Yellow Drake) Mayfly NymphEphemera varia (Yellow Drake) Mayfly Nymph View 4 Pictures
Collected March 29, 2006 from in
Added to Troutnut.com by on April 6, 2006
Female Ephemera varia (Yellow Drake) Mayfly DunFemale Ephemera varia (Yellow Drake) Mayfly Dun View 7 PicturesThis yellow drake dun hatched out of my aquarium over a month before her brethren in the wild are slated to emerge. She seems a bit small, and that might be the reason.
Collected May 13, 2007 from in
Added to Troutnut.com by on May 18, 2007
Female Ephemera varia (Yellow Drake) Mayfly SpinnerFemale Ephemera varia (Yellow Drake) Mayfly Spinner View 6 PicturesI found this female spinner ovipositing in a small stream. She came along while I was playing a trout -- every good bug seemed to do that last night! I didn't have my bug net, so I caught the trout in my landing net, released the trout, and caught the mayfly in my landing net. Her wing got a bit messed up from that.
Collected July 7, 2006 from in
Added to Troutnut.com by on July 8, 2006

Mayfly Species Epeorus vitreus

These are very rarely called Pale Sulphur Duns.
This is the second most common Epeorus species in the East and Midwest. Most anglers will encounter sporadic hatches of Epeorus vitreus once in a while, and sometimes a more concentrated emergence causes a good rise of fish.
Epeorus vitreus (Sulphur) Mayfly NymphEpeorus vitreus (Sulphur) Mayfly Nymph View 6 Pictures
Collected February 7, 2004 from in
Added to Troutnut.com by on January 25, 2006
Male Epeorus vitreus (Sulphur) Mayfly DunMale Epeorus vitreus (Sulphur) Mayfly Dun View 4 PicturesThis is my favorite mayfly from 2004, and it appears on my popular Be the Trout: Eat Mayflies products. Check them out!

Its identification is really up in the air. It might be a late-season vitreus dun but it may very well be one of the more obscure species in that genus.
Collected September 2, 2004 from in
Added to Troutnut.com by on January 25, 2006
Female Epeorus vitreus (Sulphur) Mayfly SpinnerFemale Epeorus vitreus (Sulphur) Mayfly Spinner View 9 Pictures
Collected September 19, 2006 from in
Added to Troutnut.com by on October 4, 2006
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