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Topic: Mayfly - Timpanoga hecuba pacifica - nymph
TaxonJan 30, 2011 22:43 0012-0001

WA, USA

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Identify the genus and species by the ventral view of this mayfly nymph which was collected from the S. Fork Snoqualmie River on August 18, 2007. Incidentally, the dorsal photo I took of it was in really poor focus, and by the time I discovered that, the tails had already broken off, so re-photographing it was not a practical option.


Roger Rohrbeck
EntomanJan 31, 2011 11:58 0012-0002

Northern California

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Hi Roger,

If larger than an inch - Horseshoe Crab

If smaller than an inch - Timpanoga hecuba (Family Ephemereliidae). Being a coastal specimen, I'll take it a step further and go with subspecies pacifica (or have those pesky revisionists recently made them synonymous).

The inland subspecies T. hecuba hecuba is fairly prolific on the Truckee which drains the east slope of the Sierras. They like the silt; which may explain why they seem to do better in cycles of low spring runoff, which is when fishable numbers are usually reported. They are the largest mayflies on many Western freestone rivers, rivaling their Drunella grandis (var. subspecies) cousins in length and as the picture shows, beating them substantially in robustness. I've captured specimens on the Truckee as large as 18 mm! They go by the names Brown Drake and Dk. Green Drake which are misnomers, being that both have already been applied to Ephemerids. Besides, there's nothing green about them. I prefer Western Red Drake or Great Red Quill to avoid confusion and in keeping with fly fishing's tradition of often labeling brown flies ''red''.

Regards,

Kurt
Entoman
TaxonFeb 04, 2011 05:15 0012-0003

WA, USA

Topics started: 127
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If larger than an inch - Horseshoe Crab
Now, that is funny!
I've captured specimens on the Truckee as large as 18 mm!
Yeah, they are large buggers.
They go by the names Brown Drake and Dk. Green Drake which are misnomers, being that both have already been applied to Ephemerids. Besides, there's nothing green about them. I prefer Western Red Drake or Great Red Quill to avoid confusion and in keeping with fly fishing's tradition of often labeling brown flies ''red''.
Rick Hafele, arguably the leading entomologist/flyfishing writer in the Pacific Northwest, and someone I really look up to, calls them Great Blue-Winged Red Quills. However, that name is such a mouth-full, that I never can remember it, so I simply refer to them as Timpanoga hecuba.


Roger Rohrbeck
EntomanFeb 04, 2011 21:41 0012-0004

Northern California

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Hi Roger -

Was I right about pacifica? I wouldn't have a clue how to tell the difference myself, it was just a guess based on distribution. For all I know it may no longer be considered a subspecies anyway. Just curious.

Rick Hafele... Really!! Goes to show great minds think alike! I agree that's a pretty long handle. Even Great Red Quill's a bit much for practical converstation. I'm no fan of acronyms though. ''BWO'' & ''PMD'' are bad enough, but ''GRQ'' is definitely out of the question. I feel even stronger about butchered scientific names like Flav's, Trico's... Heck's? Cuba's? I don't think so..... I'll settle for Red Drake, it's easier, and can't be confused with any other mayfly (not that anybody gives a damn what I call anything).


Kurt
Entoman
TaxonFeb 05, 2011 00:24 0012-0005

WA, USA

Topics started: 127
Replies made:  623
Kurt-

In 2002 Pat Randolph listed the distribution as:

Timpanoga hecuba (Eaton)
CanadaŚAB,BC.
USAŚCA,CO,ID,MT,NM,NV,OR,UT,WA.

And currently, Mayfly Central (Pat McCafferty) lists the distribution as:

Timpanoga hecuba hecuba (Eaton), 1884 [CAN:NW;USA:NW,SW]
* Ephemerella hecuba Eaton, 1884 (orig.)
* Ephemerella hecuba hecuba Eaton, 1884 (stat.)

Timpanoga hecuba pacifica (Allen & Edmunds), 1959 [USA:NW]
* Ephemerella hecuba pacifica Allen & Edmunds, 1959 (orig.)

As to distinguishing the nymphs of one subspecies from another, I wouldn't be surprised if that can't even be done, and would require rearing nymphs to imago lifestage, and then examining genitalia of the males. However, I really don't know that, so this is yet another subject that it would be nice if konchu could weigh in on.


Roger Rohrbeck
EntomanFeb 05, 2011 18:53 0012-0006

Northern California

Topics started: 55
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Roger - Yeah, That's what I thought too. I think that Konchu is probably going to say the same thing. You never know though, I think he posted a reply on trout nut regarding parasites where he identified a Baetisca nymph from a closeup of only a small portion of the head! He did it in the form of a question for CYA, but still... Amazing!

Left me thinking, ''How'd he do that?'' until I saw a portion of the antennea in it. I wouldn't have made that connection in a million years on my own.

Kurt

Entoman
EntomanFeb 07, 2011 11:04 0012-0007

Northern California

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Hi Roger,

Oh, you made a comment earlier in the thread I can't let go unaddressed, to wit:
Great Blue-Winged Red Quills. However, that name is such a mouth-full, that I never can remember it, so I simply refer to them as Timpanoga hecuba.


Only a true bug fanatic could admit to that!! I don't think there's one in ten thousand fly fishermen that can even pronounce ''Timpanoga hecuba'' correctly (I'm not even sure I am), let alone remember it!

Kurt
Entoman
TaxonFeb 07, 2011 11:39 0012-0008

WA, USA

Topics started: 127
Replies made:  623
Kurt-

Ha. Who said anything about pronouncing? Heaven forbid.


Roger Rohrbeck
jmw975Aug 12, 2011 04:56 0012-0009

Guelph, Ontario

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Replies made:  2
I know this thread has been inactive for quite a while, but I just have to say I think this is one of the coolest species of mayflies in North America. It's so bizarre!

Jeff
TaxonAug 12, 2011 09:44 0012-0010

WA, USA

Topics started: 127
Replies made:  623
Hi Jeff-

Yes, I certainly agree. Do you have any insight regarding differentiation of nymphal Timpanoga hecuba hecuba from T. hecuba pacifica?







Roger Rohrbeck
EntomanDec 12, 2011 17:46 0012-0011

Northern California

Topics started: 55
Replies made:  783
Hi Roger,

Though not listed for WA as late as Meyer & McCafferty '07, this may indeed be E. h. pacifica as they do not go to the sub-specific level. The following is a quote from MONACA:
Allen & Edmunds (1959) provide characters to distinguish the nymphs of the subspecies, but E. h. pacifica is distributed west of the Cascades and the Sierra Nevada and E. h. hecuba is distributed east of the Cascades and the Sierra Nevada through the Rocky Mountains.
Regards,

Kurt
Entoman
EntomanJan 15, 2013 01:39 0012-0012

Northern California

Topics started: 55
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Hi Roger -

Was reading Allen & Edmunds '59 and came across some enlightening info regarding this critter. First off, the only geographic location where the two subspecies meet is a narrow band at the CA/OR border inhabited by a population of intergrades. The distribution pattern forms an ''H'' as everywhere else the distance between them is hundreds of miles. If this specimen were taken from the western half of WA it must be h. pacifica.

Perhaps more significantly, there is also an easy character difference mentioned - pacifica has paired dorsal spines on the terga while these are absent on hecuba.

Regards,

Kurt
Entoman
TaxonJan 17, 2013 23:37 0012-0013

WA, USA

Topics started: 127
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Yes it was collected in W. WA, so it must be T. hecuba pacifica. However, now that you have shared what to look for, I'll dig the specimen out of its vial, put it under the microscope, and share some dorsal images with you.
Roger Rohrbeck
TaxonJan 17, 2013 23:43 0012-0014

WA, USA

Topics started: 127
Replies made:  623
Hi Kurt,

Ah, I see, the warning messages are still there. Guess I misunderstood you, as I thought they appeared when one went to preview a post, but they don't appear until you actually post the information. Well, hopefully I can fix that too.
Roger Rohrbeck
EntomanJan 19, 2013 01:24 0012-0015

Northern California

Topics started: 55
Replies made:  783
So far so good from my end. I can edit older posts again. I haven't tried to preview and then go back and change something un-posted yet. Will let you know when I try.

It will be very interesting to see what dorsals of your hecuba specimen show.


Entoman
TaxonJan 19, 2013 02:08 0012-0016

WA, USA

Topics started: 127
Replies made:  623

Okay Kurt, here is a full dorsal. Just circle whatever area or areas you would like me to zoom in on, and I'll take more photos.
Roger Rohrbeck
EntomanJan 19, 2013 11:58 0012-0017

Northern California

Topics started: 55
Replies made:  783
Ah! Now we have a dorsal habitus in the thread. Very good! I can just make out the paired projections in the photo. For a better look, the specific area of interest is probably terga 3 & 4 as they are the ones diagrammed in Allen & Edmunds '58. However, any of the terga between 3 and 7 should show them just as well. The examples in the paper show varying degrees of projection for pacifica - from very noticeable spikes to small bumps. With hecuba, the tergal posterior margins are completely smooth.
Entoman
TaxonJan 21, 2013 03:23 0012-0018

WA, USA

Topics started: 127
Replies made:  623

Kurt-

Okay, I believe they show up in this view. Please see white circled areas above.
Roger Rohrbeck
EntomanJan 21, 2013 12:36 0012-0019

Northern California

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Yep, those are them. That scope comes in pretty handy...
Entoman
TaxonJan 21, 2013 18:22 0012-0020

WA, USA

Topics started: 127
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Hi Kurt,

Well that's certainly relief. I had to look up the paper (which proved somewhat difficult) to see the illustrations, so I would know what exactly what to look for, and where exactly to look, and even then it was difficult to spot the protrusions, and even more difficult to get an acceptable image of them. Perhaps the protrusions would have been easier to spot on a fresher specimen, as opposed to one which had been preserved for over five years; just don't know.


Roger Rohrbeck
EntomanJan 22, 2013 19:12 0012-0021

Northern California

Topics started: 55
Replies made:  783
Perhaps the protrusions would have been easier to spot on a fresher specimen, as opposed to one which had been preserved for over five years; just don't know

Undoubtedly... The other issue is that tubercles are often just darned tough to make out in dorsal shots. It never ceases to amaze me (the difference) when we get a chance to look at a good lateral. Ones that you can barely make out suddenly stick out like sore thumbs. That's why your scope is so valuable. You may not win any photo awards with it, but we can sure see what we're trying to see.

BTW - We've certainly come a long way with this one, haven't we?

Entoman
TaxonFeb 09, 2013 05:50 0012-0022

WA, USA

Topics started: 127
Replies made:  623
Hi Kurt-

Don't think I've made any significant contribution to our progress, but thanks for the reminder that I had failed to assign it to the subspecies that we agree it is.
Roger Rohrbeck


Created: 01/12/2010   Last modified: 12/26/2014    www.FlyfishingEntomology.com