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This is one of the species that seem to be prevalent in our area of southwest NC. It emerges in March as I recall and again in October on certain streams. I would like to confirm that this next season.

You're positive it's again in October?

That miiiight be possible since you do have a much longer season there, but I've never heard of any Leptophlebia species being multibrooded. It would be neat if that's really what you've got.

Is there any chance you've mistaken it for some similar-looking species, maybe an Isonychia, in the fall?

I guess it's possible you've got two different but similar-looking species of Leptophlebia as well.

Do you have any pictures?

That would be cool. I would guess, however, that what you're seeing are sister Paraleptophlebia hatches rather than Leptophlebia. Most "paraleps" are so similar that they are easily mistaken for the same species. We actually have three "waves" of paraleps in PA. April, June, and September. All are nearly identical in size and color, yet five species are involved. How big are the flies you are seeing?

DarkDun-

Species of family Leptophlebiidae (Leptophlebiids) are either univoltine (one generation per year), or semivoltine (one generation every two years). Leptophlebia cupida is univoltine, emerging in spring of each year.

The Leptophlebia species emerging in southwest N. Carolina would most likely be L. intermedia. Duns (subimagos) and spinners (imagos) of Leptophlebia species are fairly easy to identify, as least if you are able to catch and examine one, as they have a significantly smaller-diameter and shorter middle tail, as can be seen in the photo above.

I've actually seen another Leptophlebia from western NC. But I don't think I've ever seen autumn adults. Of course, that doesn't necessarily mean very much...

I just wanted to take a moment to clarify and amend my earlier post. When I said that "Most 'paraleps' are so similar that they are easily mistaken for the same species," I didn't mean to imply that they are easily mistaken for Leptophlebia species (though I did think that there might have been some name confusion). As duns, most Eastern Paraleptophlebia are very much alike in color and size (usually 6-8mm). The species are more readily differentiated as nymphs (some have tusks or differing head shapes, and the gill structures are different, though this requires some magnification to see). The male spinners of a few of the mid- to late-season "paralep" species also display the distinctive "jenny spinner" appearance (a white abdomen with a dark tip).

As Roger mentioned, the thinner, shorter middle "tail" is a pretty definitive field identification trait for Leptophlebia. (Anthopotamus adults also have this tail configuration, but I doubt that anyone could confuse "golden drakes" for "black quills.") In addition, Leptophlebia adults are larger (abt. 10-12mm), somewhat darker, and stouter-bodied than Paraleptophlebia adults.

That said, I'd also have to say that my earlier guess about Paraleptophlebia being a candidate for DarkDun's March/October hatch is unfounded. A quick check of the NC collecting record shows a complete absence of Paraleptophlebia species. I find this surprising, as there are a number of Paraleptophlebia spp. that range into the Southeast. Perhaps the NC collecting record is relatively incomplete, but without any evidence of paraleps in the record, I humbly and respectfully withdraw my earlier speculation! :)

While looking at the NC record, I did note that (in addition to intermedia) Leptophlebia bradleyi and Habrophlebia vibrans are also listed. Perhaps one of these species is the other Leptophlebia that Konchu is seeing.

Gonzo-



Withdrawal of you humble and respectful earlier speculation is unnecessary. In his doctoral dissertation, John Randolph (of Mayfly Central) listed the following Leptophlebiids as being present in N. Carolina:

Leptophlebiidae Habrophlebia vibrans Needham, 1907
Leptophlebiidae Habrophlebiodes americana (Banks), 1903
Leptophlebiidae Leptophlebia bradleyi Needham, 1932
Leptophlebiidae Leptophlebia cupida (Say), 1823
Leptophlebiidae Leptophlebia intermedia (Traver), 1932
Leptophlebiidae Leptophlebia johnsoni McDunnough, 1924
Leptophlebiidae Paraleptophlebia adoptiva (McDunnough), 1929
Leptophlebiidae Paraleptophlebia assimilis (Banks), 1914
Leptophlebiidae Paraleptophlebia debilis (Walker), 1853
Leptophlebiidae Paraleptophlebia guttata (McDunnough), 1924
Leptophlebiidae Paraleptophlebia moerens (McDunnough), 1924
Leptophlebiidae Paraleptophlebia mollis (Eaton), 1871
Leptophlebiidae Paraleptophlebia swannanoa (Traver), 1932
Leptophlebiidae Paraleptophlebia volitans (McDunnough), 1924

Additionally, per Dr. Michael Hubbard, Florida A&M University and Ephemeroptera Galactica, the following Leptophlebiid species would also be present in N. Carolina:

Leptophlebiidae Choroterpes basalis (Banks), 1900

Incidentally, the mayfly distribution for any USA state can be viewed by clicking here, entering the two letter state abbreviation in the box for USA (state), and clicking the Submit Query button.

I've not been to flyfishingentomology.com before. Nice. What is the basis for the geographic distributions returned from each query?

Konchu-

The N. American Region distributions come from the Mayfly Central's The Mayflies of North America (last updated: August 30, 2006) Master Species List, which was developed and is maintained by Dr. W. Patrick McCafferty.

The N. American State and Province distributions come from Distribution of mayfly species in North America, an excerpt from John Patrick (Pat) Randolph's doctoral dissertation hosted at BugLab.

EDIT:

Thanks for pointing that out, Konchu. Have now footnoted the page to attribute source of distribution data.

Thank you, Roger--you are amazing! Apparently the resource I have been using to check on national distribution is woefully incomplete and out-of-date. I just compared the PA mayfly lists. The old one is useless and the new one looks spot on. (The site I had been using is a government resource. Go figure.) Thanks for another great addition to my "favorites" list. I hereby humbly and respectfully reinstate my previous speculation! :)

You're welcome, Gonzo. However, the truth be know, probably the only thing amazing about me is the depth of my obsession. In any event, I'm familiar with the mayfly distribution site you have been using. Its distribution is based on extraction from numerous books and scientific papers, and as a result has spotty coverage, both on a species and location basis. On the other hand, when it says a particular species is present in a particular county, it is likely quite accurate.

You're too humble, Roger. Depth of obsession is a quality I admire (politely referred to as "passion"). I agree about the other site--when 10 out of the 12 Ephemerellidae listed for my home state are Eurylophella spp. and the other two are Attenella attenuata and Timpanoga lita, it's pretty obvious that some glaring gaps and omissions exist!

I wasn't aware that part of that disseration was available Online. How long has it been there?

Gonzo-

Yes, it's unfortunate that site's coverage isn't more complete, as the interface is really great. Incredibly, the site doesn't list a single Baetidae species for WA, and we have at least (6) species with reasonably wide distribution statewide, and numerous others less commonly discovered in kicknet samples.

Konchu-



Not exactly sure. Discovered it seven months ago (in April). It may have been put online by BugLab as long as nine months prior to that, which would coincide with its presentation at the Xerces Mayfly Festival.

The species I originally noted, Leptoplebia, was in the 10 to 12 MM lentgth and 3 tailed. I am now thinking it may be a Rhithrogena Impersonata (10-12 MM) or possibly Ameletus Ludens (10-14 MM) as described in the book MAYFLIES by ROBERT CORMIER.
This fly is a fast water emerger, in the riffles, and some of the flies seem to be 12 to 13 MM in size verging on being Stenonema Vicarium sized. Wings are a smoky dark gray. Eyes are large and deep brown on the specimens I have captured. Body is a deep brownish on the dun.

Dark Dun,

Both Rithrogena and Ameletus would be two-tailed as adults. You didn't specify, but if that's the case, you may be on to something. Both genera are rather uncommon in the East, but as I am not too familiar with southern distribution, that's about all I can say. The nymphs would be quite different--the former is a clinger and the latter a swimmer--so a search for the nymphs might solve the puzzle.

DarkDun-

The species of interest to flyfishers, which are found in the North Carolina, would come reasonably close to your body description of deep brownish and wing description of smoky dark gray, and have a dun length range encompassing the length you describe, would be the following:

Leptophlebia cupida (Black Quill) - emerges mid-Apr to late-Aug
Drunella walkeri (Slate Drake) - emerges mid-Jul to mid-Sep

So, I would guess you are encountering Black Quills in March, and (somewhat-delayed-emerging) Slate Drakes in October.

DarkDun and Roger,

I'm a little puzzled as to whether we are discussing a two- or three-tailed dun here. The problem I see with Leptophlebia cupida as a candidate is that DD's last post describes a fastwater emerger and that is contrary to what I know of cupida habitat and emergence. (It is usually a "frog-water" type.) D. walkeri, on the other hand, likes the fastwater stretches and could be a good candidate for the later hatches. (If DD's mystery duns are three-tailed.)

If we are talking about two-tailed duns that match the general description, I wonder about Isonychia species. While March is certainly earlier than any Iso emergence I've heard about, the later hatch is reasonable, and I believe there are some species (other than bicolor) found in the South that I'm not very familiar with. This genus also presents the possibility that the two emergences might be the same fly (or, at least, the same genus). I'm frankly confused by the whole discussion. Help!

PS--Roger, I just checked the wonderful distribution resource on your sight for NC, and I found 5 species of Iso other than bicolor (amazing variety!) and two species of Ameletus. (Though not ludens--if there really is a valid distinction between ludens and lineatus.) If it is a two-tailed dun, some combination of these may explain things.

Gonzo-

From his first post, it was my impression that DarkDun had seen mayflies in both March and October, which closely resembled Jason’s photo of winged Leptophlebia cupida. From his second post, it was my impression that he was saying the specimens he captured were 10-12 mm. in length, 3-tailed, and that the duns had smoky dark gray wings, and deep brownish bodies. It was my impression that the rest of the information in his second post related, not to the specimens he observed, but to what he was speculating they might be, and to Knopp/Cormier’s description those species.

With regard to Ameletus ludens and A. lineatus, yes they are considered to be separate species by Mayfly Central, which I consider to be “the authority” for N. American mayfly taxonomy.

Hopefully, when DarkDun next posts, he will clarify his observations, particularly whether he actually counted tails on the mayflies he observed in both May and October, and also any other information that we may have interpreted differently from his posts.