Will the real Ephemerella needhami please stand up?

The Specimen

Ephemerella needhami (Little Dark Hendrickson) Mayfly Dun

View 7 PicturesSee the comments for an interesting discussion of the identification of this dun.

Collected June 1, 2007 from the West Branch of the Delaware River in New York
Added to Troutnut.com by on June 4, 2007

The Discussion

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GONZO	July 30th, 2011, 3:49 pm
Site Editor "Bear Swamp," PA Posts: 1681	Please forgive the trite and dated "To Tell the Truth" title, but recent conversation and speculation about E. needhami subs is scattered through another thread ("Taxonomy and DNA"), so I thought I'd start this thread in an attempt to consolidate some of that conversation. The "E. needhami/Chocolate Dun" of angling lit. and popular hatch charts can be very different from the E. needhami described in the scientific literature. I'm convinced that it is often confused with Eurylophella spp. or Teloganopsis deficiens (formerly Serratella deficiens) partly because of questionable descriptions of the "blackish" wings of the duns and partly because the other genus and species are not well known to most anglers (even though they are commonly encountered on many eastern trout streams). Your Ephemerella X looks an awful lot like this guy, who I formerly had placed in a couple different species but have put with Ephemerella needhami now after Gonzo made a convincing case for it. I'm guessing the X is needhami, at least for the specimen you pictured. The one I photographed on the Delaware was a small 16 or large 18, but that's within the range of variation for a single species at different places/times. Just as a point of clarification, Jason and I have had recent discussions about this species, and I did (recently) post about the misidentification of several subs and adults (Eurylophella spp.) that were previously included on the needhami pages. However, it was Dr. David Funk's confident identification of the above specimen that seemed to seal its placement. I believe he is correct. Jason, that sure looks like it. But... I thought needhami were very dark, with blackish wings -similar to S. deficiens. That's as I remember it. Could well be wrong. That's a pretty common (mis?)conception, Paul, and I believe it can probably be traced to Caucci and Nastasi's Hatches (1975). Although McDunnough's 1931 (re)description of this species described the needhami subs as having "very pale smoky unicolorous wings," C&N's Hatches described them as "dark grey almost black." I'm convinced that the latter description is based on a misidentification because C&N's color photo, captioned "Ephemerella needhami, male dun," appears to be a Eurylophella dun. (It has the telltale long 9th abdominal segment.) Though your photo could very well be needhami, it looks like it could also be an eastern excrucians. Do you remember Gonzo's rationale? I looked for it on the hatch page but only found from my quick scan a conversation about another family. Gonzo didn't participate as far as I could tell. Just to be clear, Kurt, I did participate, to the point of initiating a previous thread about this specimen, but my participation was limited to expressing my doubts about its original placement in Serratella. PS I started to post yesterday that I thought your bug was needhami and pulled the post after a half hour or so...I had sent an email up to Gates' about a so-called "Dark Henrickson they had listed on their Hatch Chart...They wrote me back it was the web masters typo...I started to doubt myself and yanked the post. I was having doubts due to its size... Thanks, Spence. That explains the mystery of the disappearing posts. :) I'm not making an argument that Paul's mystery "Ephemerella X" dun is E. needhami. I just wanted to point out that the species is often subject to misidentification based on (some angling) descriptions that are probably attributable to other species. Only a few years after his original 1925 description, McDunnough (1931) said this: Considerable confusion has existed regarding this species; it has been misidentified as excrucians Wlsh. by Needham and, to complicate matters, its nymph has been misassociated with bispina Needh. which belongs in another section of the genus. And so it goes....

Entoman	July 30th, 2011, 5:04 pm
Northern CA & ID Posts: 2604	Hi Lloyd, Thanks for the clarification! Sometimes these threads become more like "tangled webs." :) I went back and found your comments as well as Dr. Funk's in the other thread associated with the photo's. At least that mystery has been cleared up. C&N's Hatches described them as "dark grey almost black." I'm convinced that the latter description is based on a misidentification because C&N's color photo, captioned "Ephemerella needhami, male dun," appears to be a Eurylophella dun. I agree with this assessment. Misidentification (either by photo or description) is also a problem in many other instances as well. Using angler entomologies as the basis for id's without extensive cross referencing can lead to a lot of confusion. This also makes me think of a separate but closely related point, differentiating "dun" wing color in photos. I've noticed that the variabilities involved in lighting, backround, and color reproduction (not to mention specimen variability) make discussing subtle differences in shades of "dun" largely an exercise in futility. Even fairly dark gray wings can look pretty light when well backlit. "Dorothea and grandis like" examples aside, it can get pretty tough. Heck, even with these two examples there can be "gray" areas.:) I'd sure like to hear your thoughts on the differences between needhami and the eastern variation of excrucians. Also on the separate issue of Paul's X dun, i.e. subvaria, invaria or neither? Best regards, Kurt
	"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman

GONZO	July 30th, 2011, 6:18 pm
Site Editor "Bear Swamp," PA Posts: 1681	I'd sure like to hear your thoughts on the differences between needhami and the eastern variation of excrucians. Also on the separate issue of Paul's X dun, i.e. subvaria, invaria or neither? To the best of my knowledge, I've never encountered E. excrucians on any of the eastern streams I've fished, and my impression is that they are rather rare in much of my part of the East (at least as anything that might create a steady rise of trout). Populations of E. needhami can be quite extensive on some streams, especially on streams that support seasonal growths of Cladophora alga. (See McShaffery and McCafferty, 1991, for a very thorough discussion of the association of E. needhami and Cladophora.) As for Paul's dun, my off-the-cuff impression would be neither subvaria nor invaria, FWIW. Using angler entomologies as the basis for id's without extensive cross referencing can lead to a lot of confusion. It can lead to a lot of confusion even with extensive cross-referencing. :)

Entoman	July 30th, 2011, 7:29 pm
Northern CA & ID Posts: 2604	Thanks Lloyd, My questions were a little unclear, sorry about that. I should have called them Mid-western excrucians. I was trying to differentiate them from our western PMD's so as to narrow down the comparison with needhami. I'm a little fuzzy on the difference between the two after looking close at Jason's photo in light of Dr. Funk's I.D. As to Dun X any ideas on what it could be? Its size and dramatic tail articulations rule out E. needhami & excrucians, and T. deficiens as well. S. serrata can have noticable tail articulations, but a size 14? Kurt
	"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman

GONZO	July 30th, 2011, 7:42 pm
Site Editor "Bear Swamp," PA Posts: 1681	Why do you say that the (darkened) tail articulations rule out E. needhami, E. excrucians, and T. deficiens? (I would rule out the last one, but for other reasons.)

Entoman	July 30th, 2011, 9:17 pm
Northern CA & ID Posts: 2604	Because Paul's X bug has strong articulations like subvaria. I thought the others were all whitetail bucks.:) It can lead to a lot of confusion even with extensive cross-referencing. :) Ain't it the truth! :)
	"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman

PaulRoberts	July 30th, 2011, 10:07 pm
Colorado Posts: 1776	I've fished Eurylophella emergences on the Big D. The adult nymphs are easily recognized with their silt flaps over the gills. I really enjoyed them bc they emerged along slow shorelines where many big Delaware browns hung out. And no one else was hip to them at the time. In fact, I hit a great emergence at the West Branch Angler Resort while running a fly-fishing camp there. Everyone waded right through them and it became a great teachable moment, even for the head guide there, who had never heard of them prior. They were about a #16 muddy-colored dun. I had a GREAT dry pattern for them on those slow bank currents, (made almost entirely from a single Canada goose body feather), as those fish could really scrutinize a fly. I published that fly in Fly Fisherman as the "UltDun" -the most realistic dun I've fished. As to needhami, it's quite possible that I took the "blackish" look from C&N. However, I doubt I'd confuse them with deficiens (Tellagnopsis/Seratlella) duns, as I felt they were easy to recognize with their small size and compact bodies. My memory tells me needhami was longer but colored like deficiens. But I don't have any images of them so I don't really know whether I collected any adults or whether I just I'm just remembering C&N. One of these evenings when I can clear the time I'll dig back into my journals and see if I'd collected any at one time or another. I do remember collecting some needhami nymphs, with their longitudinal stripes and am quite sure I had some in my stream tank at one time. Now I'm wondering of THOSE were excrucians or needhami. I was keying nymphs out at the time and, unless the key wasn't up to date then, or I missed something, decided on needhami.

GONZO	July 30th, 2011, 10:29 pm
Site Editor "Bear Swamp," PA Posts: 1681	I thought the others were all whitetail bucks.:) All of those species (including the inermis version of excrucians) are described as having darkened tail articulations in Allen and Edmunds (1965). I have seen E. needhami and T. deficiens (duns) whose tail markings were faint to almost nonexistent. I don't have enough personal experience with E. excrucians to comment beyond what I read in the literature. However, I doubt I'd confuse them with deficiens (Tellagnopsis/Seratlella) duns, as I felt they were easy to recognize with their small size and compact bodies. Agreed, Paul, and those little "Darth Vader" duns (especially those on the Beaverkill) often come closer to actually having black wings than any mayfly I regularly encounter. In my experience, the wings of most E. needhami duns are closer to McDunnough's "very pale smoky" description than C&N's "almost black" (which is a better description of the wings of some Eurylophella duns).

Entoman	July 31st, 2011, 2:08 am
Northern CA & ID Posts: 2604	Lloyd - All of those species (including the inermis version of excrucians) are described as having darkened tail articulations in Allen and Edmunds (1965). I have seen E. needhami and T. deficiens (duns) whose tail markings were faint to almost nonexistent. I don't have enough personal experience with E. excrucians to comment beyond what I read in the literature. Well... What we can gleen from all this tail business is ... I'm not sure! I have a fair amount of experience with infrequens and the old inermis versions and they do have dark articulations visible under magnification, but not that you'd notice in the hand. They just look very pale creamy. In any event both are far from the order of magnitude as in subvaria or Paul's X dun. But like you Lloyd (only reversed), I don't have much personal experience with the other little eastern critters we have been discussing, except the few photgraphs we have of them here and various angling text descriptions and photos that seem to be at odds with Allen and Edmunds. But then again, so am I regarding the western species. Hmm... Paul - I was hanging my hat on size, body color, and them speckly tails!:) If Lloyd and Luke are scratching their heads, I guess we're right back where we started. Ephemerella X:) I do remember collecting some needhami nymphs, with their longitudinal stripes and am quite sure I had some in my stream tank at one time. Now I'm wondering of THOSE were excrucians or needhami. I was keying nymphs out at the time and, unless the key wasn't up to date then, or I missed something, decided on needhami. No, I think you were right in the first place, odds are 99% those were needhami. Could they have been aurivillii? Much rarer and bigger bug back East I think. Kurt
	"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman

Oldredbarn	July 31st, 2011, 12:31 pm
Novi, MI Posts: 2608	Thanks, Spence. That explains the mystery of the disappearing posts. :) Sorry G. I must of became over excited with the discussion etc and I just leapt in to the deep end of the pool where the big "bug boys" swim before I realized I'd forgotten my flotation device...:) Not to screw with a metaphor too badly...I bailed. Spence
	"Even when my best efforts fail it's a satisfying challenge, and that, after all, is the essence of fly fishing." -Chauncy Lively "Envy not the man who lives beside the river, but the man the river flows through." Joseph T Heywood

GONZO	July 31st, 2011, 12:54 pm
Site Editor "Bear Swamp," PA Posts: 1681	...I bailed. There was no reason to bail, Spence. For all the back and forth, needhami still seems like it might be a possibility for Paul's "X" dun, and the "big bug boys" are floundering in the deep end as well. Maybe we could all use a flotation device. :)

Entoman	July 31st, 2011, 1:09 pm
Northern CA & ID Posts: 2604	Or at least be current in CPR:)
	"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman

PaulRoberts	July 31st, 2011, 2:25 pm
Colorado Posts: 1776	No, I think you were right in the first place, odds are 99% those were needhami. Could they have been aurivillii? Much rarer and bigger bug back East I think. Kurt aurivillii was what I meant, not excruciens. Knopp and Cormier describe needhami as having three color morphs: a rust, a dark brown, and a brownish-olve. Now...I know those guys don't have personal exp with every mayfly and in large part are passing on what they've heard. Likely IDs were mixed up before them, so who knows. Guys, I looked closely at the hind wings from Jason's images of needhami and invaria and my image and the Needhami hindwing is more pointed and the invaria and my bug have more rounded hind wings. Dunno if that means anything, and the aspect of my image is not the same as Jason's perfect side views. Anyway, as I said I'll revisit my journals and see if I'm missing something.

GONZO	July 31st, 2011, 4:37 pm
Site Editor "Bear Swamp," PA Posts: 1681	Guys, I looked closely at the hind wings from Jason's images of needhami and invaria and my image and the Needhami hindwing is more pointed and the invaria and my bug have more rounded hind wings. Dunno if that means anything, and the aspect of my image is not the same as Jason's perfect side views. That's a good point about the hindwing shape, Paul. At one time, I thought that the difference between the more rounded hindwings and the more pointed ones that I saw in large eastern sulphurs might be a distinction between "old" rotunda and "old" invaria. Now, I think it is probably just a dimorphic difference between male and female. Although I'm not used to seeing "sulphur" duns as dark as your specimen (the male spinners are often dark brown), it may well be that it is just a dark specimen of invaria (or perhaps more properly, the invaria species group?) as you suggested earlier. Cf Jason's specimen here: http://www.troutnut.com/specimen/178

Entoman	July 31st, 2011, 4:53 pm
Northern CA & ID Posts: 2604	Hi Paul, About the confusion over excrucians, I figured as much which is why I didn't mention it. What are talking about now... 6, 7, 8 species? I've lost count and had to go back and edit a few names myself.:) While on the subject of clearing the record, please don't anybody take my 99% literally. That was just a hyperbolic turn of phrase signifying very high probability. I see we're also on the same page regarding comparisons of your X dun to needhami. In light of Dr. funks appraisal that Jason's photo is definitely needhami, I don't see how your X dun could be the same species. Besides size and color, the anatomical differences are about as great as a comparison can be among ephemerellids. Perhaps they're all X duns.:) Kurt
	"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman

Entoman	July 31st, 2011, 8:19 pm
Northern CA & ID Posts: 2604	I find for myself it's sometimes good just to step back a little and look at the critters holistically. I often get so wrapped up in the bend of a wing vein or shape of an eye that I lose my sense of perspective. Compound that by comparing contradictory notes from a dozen different texts and voila! Confusion where there shouldn't be.... It's like looking at photos of Lady GaGa and Marilyn Monroe. If I focus in on the eye lash patterns and hairlines, I'd probably have a tough time telling them apart. When backing off on the magnification to see the whole face, the difference becomes readily apparent. Bad analogy I know, but the best I could come up with at the moment.:) Regards, Kurt
	"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman

PaulRoberts	August 2nd, 2011, 9:33 am
Colorado Posts: 1776	Well... this reminds me of the time I tried to ask an archeologist about a bone I'd found. He just seemed exasperated by the questions and finally set me straight saying that without the site--the particulars about the deposit--the fossil is all but useless. I checked my journals and did not find the record of its capture. All I can say is what is coded on the slide frame. This dun emerged from my stream tank on May 22, 1997. The unidentified nymph was collected from Mill Creek, a tiny trib of Fall Creek near Ithaca, not from Owasco Inlet as previously stated. I thought I might find that it was indeed needhami, as I'd collected some needhami nymphs (or aurivillii) and might have had them in my tank. No such luck. Dunno who that dun was. Mill Creek btw does not contain vegetation, but is a small farm/cattle degraded trib with much silted cobble. It has some springs I never located (on private property above my collection near the Fall Creek confluence) evidenced by brook trout found at the collection site. The spinner falls on Owasco Inlet I mentioned in the original post were a #16 (not #14) "dark root beer brown" Ephemerella spinner who's ID I wasn't sure of. What bothered me was the generally smaller size (I knew invaria as a #14) and, especially, it had a shorter abdomen. I saw those early eastern Ephemerella (subvaria and invaria) as having long abdomens. This one had a shorter abd and a proportionally thicker thorax -more compact looking. My nymph sampling during that period (Mid-May) turned up what I described in my journal as "invaria ready to pop with dark wing pads, dorothea's immature yet". I see in some of Jason's pics, some "invaria" with what appear to be short abdomens, both a male and a female: http://www.troutnut.com/specimen/182 http://www.troutnut.com/specimen/179 (Interestingly, these two were collected on May 23, and 22, the same date as my so-called “Eph X” -although from an entirely different state.) Likely, invaria is a morphologically highly variable species. Caucci's "Ephemerella X" may simply demonstrate the confusion this engenders. With several simlilarly-built species (subvaria, invaria, rotunda, dorothea, excruciens, needhami) and variability within, I guess what’s really is needed is one of those vest-pocket DNA tricorders. Sure would be nice to sort them out once and for all. Then again we may just find that “invaria” esp is a variable (even plastic?) “species”. We nerdy types might just be left wandering the wilderness with Spence (albeit generally happy). One last observation: On the streams I fished around Ithaca, subvaria and invaria appeared to overlap a week or so with my journals recording my seeing "a #14 sulphur (likely invaria)" while I was fishing the last of the subvaria spinner falls during the first week in May. By the second week in May it was all X/invaria. Has there ever been any evidence of hybridization?

Martinlf	February 26th, 2016, 5:15 pm
Moderator Palmyra PA Posts: 3233	Wow. I don't recall this thread at all. Thanks, Eric. Much to consider here.
	"He spread them a yard and a half. 'And every one that got away is this big.'" --Fred Chappell

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Troutnut Forum > Specimen Discussion > Will the real Ephemerella needhami please stand up?

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