Mayfly Family Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs)

Here's another hatching mayfly, this one stillborn. Click on "31 more specimens" and scroll down.

Click on "40 more specimens" and scroll down for one photo.

Some of our forum members who share my bug-geeky tendencies will be interested to know that Konchu (Luke Jacobus) has recently published a worldwide revision of the Ephemerellinae. I recently made a passing reference to his work in another thread ("changing water level"). From a fly-fishing perspective, this group includes some of our most famous and important mayflies. Most of the scientific names for famous fly-fishing hatches remain relatively unchanged (a relief for those who dislike learning new names), but there are some subtle changes and new names for a few hatches that are less famous.

Here are a few notes about species important to (North American) fly fishers:

Hendrickson (east/central)--still Ephemerella subvaria.

Large Sulphur/PED (east/central)--still Ephemerella invaria. Konchu notes that further research and clarification is needed for this species/complex (incorporating the former E. rotunda).

Small Sulphur/PED/PMD (east/west)--still Ephemerella dorothea, though (as I read it) E. infrequens is listed as a synonym rather than a subspecies. The need for further research is also indicated for this species/complex. (The other PMD, E. excrucians, is unchanged, still synonymous with E. inermis.)

Olive Morning Duns/BWOs (east)--Previously synonymized with Drunella lata, the former species cornuta and cornutella have been reinstated to full species status. The status of D. longicornus is uncertain, and more research is indicated in order to further clarify this group.

Western Green Drakes (west)--Drunella doddsii and grandis continue to be the names of the famous large WGDs, and Drunella flavilinea is unchanged for the small WGD or "Flav."

Little Black Quill/Darth Vader (east)--Not as famous as some in this group, this distinctive little black species is widespread and often important. Formerly Serratella deficiens, it is now Teloganopsis deficiens. It is the only Nearctic representative of this mostly Palearctic/Oriental genus.

Large Leggy Sulphur (east)--Although this species is not well known (and possibly not very important to fly fishers), it has been discussed on this site, and Jason has photographed it. Formerly Ephemerella septentrionalis, it is now Penelomax septentrionalis. This new genus is monotypical.

You can find a link to an overview of this revision (along with other useful/interesting info) on Konchu's website: http://mypage.iu.edu/~lmjacobu/mayfly.html
I'm sure he would be willing to answer any questions that members might have about this revision/group.

I watched quite a few of these guys emerge tonight. (I think -- they seemed too small and light to be Ephemerella invaria, though I didn't bring one home to check under the microscope.) It was a cool evening but not cold, and they were emerging on the slow flats of a large midwestern spring creek. I watched several of them drift 50+ feet on the very slow-moving water, slowly rising up out of the surface film. Their emergence was sporadic and lucky for them the trout were also sporadic. Many were eaten but others went ignored for their entire lengthy drifts.

Later in the evening I was bested by a half-dozen rising trout. The sulphurs were still emerging, and a mix of spinners was starting to appear on the water, but I didn't get so much as a splashy refusal from several rising fish, even in the low light of dusk. My best guess is that they were picky feeders keying on a stage of Ephemerella dorothea mayflies.

Hey Jason:

There are some beautiful photos posted on that forum under the "Fishing" section, and titled "Bugs are cool". My guesses as to ID are: first 2 pics (same fly)- Stenacron (orange tint, two tails, mottled wing and banded femur), third pic - Ephemerella Attenella (3 tails, slate wings and faded olive body), last 2 pics (same fly) would appear to be Maccafertium (Grey Fox - not March Brown) based on 2 tails and light coloration. Am I correct in my assumptions? Any help you could provide would be appreciated. Thanks.

JPSully