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CrepuscularApril 4th, 2012, 4:47 pm
Boiling Springs, PA

Posts: 919
I collected all of these from the same rock. The nymph on the right might be Epeorus fragilis. Close ups are all of the one on the right




EntomanApril 4th, 2012, 5:35 pm
Northern CA & ID

Posts: 2604
Wow, You have a cornucopia there!:)

The four on the left look to be vitreus. The big boy in the center is pleuralis? The far right one and the little guy below and to the left are probably fragilis. Based on the substantially different levels of development, I have my concerns whether they are the same species though. Could one be the very similar appearing frisoni? I don't think the latter has been recorded for PA - yet. When I get home this evening, I'll look into it.
"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
FalsiflyApril 4th, 2012, 5:54 pm
Hayward, WI.

Posts: 657
Wow, You have a cornucopia there!:)

So Kurt, which one is the cornucopia? Just curious, I want to stay on top of things.:)

Eric, were those taken with a new camera?

Falsifly
When asked what I just caught that monster on I showed him. He put on his magnifiers and said, "I can't believe they can see that."
CrepuscularApril 4th, 2012, 6:21 pm
Boiling Springs, PA

Posts: 919
No new camera yet. Taken through my scope.
EntomanApril 4th, 2012, 10:27 pm
Northern CA & ID

Posts: 2604
Just curious, I want to stay on top of things.:)

No problem, Al. I was excitedly referring to the very rare E. cornucopia and forgot to italicize. It's the one in the photo...:)

Eric - Are you able to look at their femoral flanges and gills from the first segments? Also, what about punctatus as a possibility in this mix? The four on the left I'd break into two groups and look closer at them. The top ones are marked a little differently from the bottom two.



"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
CrepuscularApril 4th, 2012, 11:28 pm
Boiling Springs, PA

Posts: 919

Eric - Are you able to look at their femoral flanges and gills from the first segments? Also, what about punctatus as a possibility in this mix? The four on the left I'd break into two groups and look closer at them. The top ones are marked a little differently from the bottom two.





Well I won't be back in the office until Monday so it will have to wait until then to get some more photos. What exactly are you looking for? Gills on seg 1 are elongated. I was really relying on the head capsule outer margin with abrupt transition near outer anterior corners of compound eyes which is one character that separates fragilis from frisoni in Burian 2008.
But punctatus isn't even included in that key.

As far as the E. vitreus on the left in the photo I'm pretty sure they are all the same but I'll have to take a closer look. They've been pickled for a week so some may have faded etc.
JesseApril 4th, 2012, 11:47 pm
Posts: 378
They are some really great shots!
Most of us fish our whole lives..not knowing its not the fish that we are after.
http://www.filingoflyfishing.com
EntomanApril 5th, 2012, 1:35 am
Northern CA & ID

Posts: 2604
I was asking about the femoral flanges and gills of all the specimens. What I'm looking for is whether the flanges are blunt or pointed. As far as the gills, whether they are elongate or not and whether the sclerotized strip is angled at about 45 or 90 is also helpful. A ventral of the posterolateral spines is useful for the same reason.

I was really relying on the head capsule outer margin with abrupt transition near outer anterior corners of compound eyes which is one character that separates fragilis from frisoni

That would be diagnostic if this were a New England male. The lack of concavity of the mesonotum bothers me not a little, too.
"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
KonchuApril 5th, 2012, 9:09 am
Site Editor
Indiana

Posts: 498
Epeorus frisoni probably has a very restricted range of geographic distribution, so be cautious.
EntomanApril 5th, 2012, 3:55 pm
Northern CA & ID

Posts: 2604
You are right, Luke. I understand that frisoni is a larger species found at higher elevations further North. Just looking to eliminate the possibilities by means other than distribution, if possible. The size difference between the far right specimen and the little one below it is interesting. Isn't size one way to discriminate between the two species? Can there be this much size discrepancy within the species at this time of year?

The four on the left also intrigue me. At first I thought they were just variations of the same species, but look at the terga. The upper two specimens are marked identically and the bottom two are marked identically.
"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
CrepuscularApril 5th, 2012, 9:26 pm
Boiling Springs, PA

Posts: 919
What's a matter Kurt? Three species from the same rock isn't enough for you? ;).I would not be surprised to see a difference in size. How about male vs female? The E. vitreus on the left are different sizes no? All of the head capsules look the same.
FalsiflyApril 5th, 2012, 9:51 pm
Hayward, WI.

Posts: 657
The size difference between the far right specimen and the little one below it is interesting. Isn't size one way to discriminate between the two species? Can there be this much size discrepancy within the species at this time of year?

But notice the difference in wing pad development, couldn't this just be a difference in instar?
Falsifly
When asked what I just caught that monster on I showed him. He put on his magnifiers and said, "I can't believe they can see that."
EntomanApril 5th, 2012, 10:51 pm
Northern CA & ID

Posts: 2604
Eric -

A triple is nice, but maybe you hit a home run!:)

The E. vitreus on the left are different sizes no? All of the head capsules look the same.

Yes. That is confirmed now with your latest photo. The fascinating thing is there are two with dark tergal rectangles in both sizes and two with dark triangles in both sizes. I assumed it's because you have both male and female represented (one in each size which is cool), but couldn't quite make out their entire heads to know for sure.

Al -

But notice the difference in wing pad development, couldn't this just be a difference in instar?

Yes. That's correct. What is interesting though is how far behind. Unless it's a different species, its hatches must trickle off in very low numbers over a long period, even if the nymphs are abdundant.

BTW - Thank you both for confirming my original calls with such conviction. I'll stop second guessing myself now... See how I cover my bases?:)
"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
CrepuscularApril 6th, 2012, 12:17 am
Boiling Springs, PA

Posts: 919
I still want to be sure that it's E. fragilis. I sent some photos to D. Funk at Stroud but haven't heard back. He said he has never collected it in PA. I have two others I'd like to talk to about it. Luke what do you think? I'd like to hear Gonzo's opinion as well.
EntomanApril 6th, 2012, 1:42 am
Northern CA & ID

Posts: 2604
Eric -

Luke what do you think? I'd like to hear Gonzo's opinion as well.

Me too. Though, I'm reasonably confident in fragilis.

I still want to be sure that it's E. fragilis. I sent some photos to D. Funk at Stroud but haven't heard back. He said he has never collected it in PA.

Maybe he hasn't, but others have. The species is reported from PA.
"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
KonchuApril 6th, 2012, 8:01 pm
Site Editor
Indiana

Posts: 498
When were these collected? How big?
CrepuscularApril 7th, 2012, 2:44 pm
Boiling Springs, PA

Posts: 919
Luke they were collected March 30th. The E. fragilis is about 9mm.
EntomanApril 7th, 2012, 3:04 pm
Northern CA & ID

Posts: 2604
Isn't that way too big for fragilis? Even the matures are supposed to be well under 7mm. This new info shoots a big hole in my previously expressed confidence.:)

Not to throw more cold water on our attempts, but...

Burian, et. al. - 2008

After studying the New England subset of the eastern Nearctic species of Epeorus, it is now clear that there is much unexplored variation within and among species. Many of the characters studied for larvae and adults of E. frisoni are subtle and some are within the range of variation for E. fragilis and E. pleuralis (emph. mine)... This suggests that at least some larval characters presented here as "diagnostic" may need to be modified as more material becomes available for study.

A closer look at the abdomen does show paired tergal spots.
"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
CrepuscularApril 7th, 2012, 4:18 pm
Boiling Springs, PA

Posts: 919
Maybe I'm wrong abouth the length. I am going from memory. Mine is not very good. We may need to table this until Monday. When I can look at it again. I will try an collect some more specimens as well.
EntomanApril 7th, 2012, 4:58 pm
Northern CA & ID

Posts: 2604
Sounds good.
"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
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