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Topic: Mayfly - Drunella grandis flavitincta - nymph
TaxonFeb 19, 2011 18:34 0025-0001

WA, USA

Topics started: 127
Replies made:  623

This mayfly nymph was collected in a kicknet sample from the S. Fork Snoqualmie River at the Twin Falls Trailhead in King County, WA, on 10/03/2009. Can you identify it to family, genus, and species?


Roger Rohrbeck
EntomanFeb 20, 2011 07:32 0025-0002

Northern California

Topics started: 55
Replies made:  783
Drunella grandis, with a ways to go.
Entoman
TaxonFeb 25, 2011 00:17 0025-0003

WA, USA

Topics started: 127
Replies made:  623
Kurt-

Yeah, I had reached the same conclusion.


Roger Rohrbeck
EntomanFeb 25, 2011 15:27 0025-0004

Northern California

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Roger - Be interesting to know which sub-species. Maybe difficult if this river is noted for having more than one. Any ideas?

Kurt
Entoman
TaxonFeb 25, 2011 16:55 0025-0005

WA, USA

Topics started: 127
Replies made:  623
Kurt-

Yes, I agree, it would certainly be interesting to know which Drunella grandis subspecies this is, but don't have access to subspecies distributions at a lower level (than USA: NW), and have no practical way to personally make such a determination. However, if anyone else knows, please be encouraged speak up.


Roger Rohrbeck
GONZOSep 28, 2011 23:04 0025-0006

"Bear Swamp," PA

Topics started: 4
Replies made:  163
Allen and Edmunds (1962) give a distribution map. Western WA is shown as D. g. flavitincta, and eastern WA is shown as D. g. ingens. Central WA apparently has intergrades or perhaps represents a clinal change. (D. g. grandis is shown as an interior subspecies, primarily in southeastern OR, southern ID, western WY, western CO, UT, NV, and northern AZ/NM.) The authors offer this caution about their proposed subspecies:
We also believe that the present treatment of E. grandis should be re-examined if future collections of series of adults reveal discordance in the geographical distribution of adult and nymphal subspecific characters.
EntomanSep 29, 2011 11:50 0025-0007

Northern California

Topics started: 55
Replies made:  783
Thanks, Lloyd.
We also believe that the present treatment of E. grandis should be re-examined if future collections of series of adults reveal discordance in the geographical distribution of adult and nymphal subspecific characters.
Since then discordance was revealed and it has been re-examined, right? Coupled with the taxonomic changes that have occurred since this paper was published? Wow...

Though I'm sure the nymphs and adults of the sub-species (as they stand now) have been fully identified and associated since the 60's and that much more is known about their distribution, am I right in also assuming that much remains unknown about their distribution and variabilities in appearance? At the risk of stating the obvious in light of the info you provided, it seems to me that trying to determine specimens to sub-species by taxonomic info available in photos and distribution records alone is probably a fool's errand (barring info that may exist on specific waters in the scientific lit. of course).

Regards,

Kurt

Edit: I noticed CA isn't mentioned, but I suspect we have a real sub-species mix down here. Substantially different eco-systems such as the Shasta region, coastal mountains, west slope Sierras, east slope Sierras, high desert, and the San Gabriels for starters are the cause. If I remember, even the relative isolation of Yosemite was considered to have a unique sub-species at one time. An interesting side-note on how far we have come (or haven't) - In Usinger (5th edition 1973), only one sub-species, grandis grandis (known at the time as E. glacialis carsona) was included for CA. According to Roger's distribution list, CA hasn't changed. This is very interesting.
Entoman
TaxonSep 29, 2011 15:33 0025-0008

WA, USA

Topics started: 127
Replies made:  623
Kurt-

Your comment about Roger's distribution raised a red flag for me, as none of the state or province mayfly distribution records I used go beyond species. So, several years ago as I recall, I made an attempt to reconcile Mayfly Central listed subspecies to state and province level distribution from Pat Randolph's dissertation. Most subspecies were obvious, but in any case where multiple subspecies were listed by M/C to exist within a specific geographic region (FN, NE, SE, NW, SW, FS), I would have had to determine the state/province distribution of that subspecies, and probably simply defaulted to the primary subspecies, which in this case would have been D. grandis grandis.

Lloyd-

Now that you have graciously pointed out a distribution map for the Drunella grandis subspecies, I will make the appropriate subspecies distribution corrections.


Roger Rohrbeck
GONZOSep 29, 2011 15:59 0025-0009

"Bear Swamp," PA

Topics started: 4
Replies made:  163
Since then discordance was revealed and it has been re-examined, right? Coupled with the taxonomic changes that have occurred since this paper was published?
No. The only significant taxonomic change to the D. grandis subspecies proposed in Allen & Edmunds has been the elevation of the subgenus Drunella to genus status.
At the risk of stating the obvious in light of the info you provided, it seems to me that trying to determine specimens to sub-species by taxonomic info available in photos and distribution records alone is probably a fool's errand (barring info that may exist on specific waters in the scientific lit. of course).
The subspecific status and indentification has not changed. If identifying traits expressed in Allen & Edmunds can be clearly seen, as far as I know, they remain the basis for subspecific determination. However, it would probably be a rare photograph (or series of photographs) that would provide this info in a useful way.
I noticed CA isn't mentioned, but I suspect we have a real sub-species mix down here.
According to Allen & Edmunds, you have no more of a subspecies mix than WA, just a different one. Most of CA is shown as D. g. ingens with some overlap and intergrades with D. g. grandis along the northeastern border with NV. (OR has all three subspecies.)

Although the status of these subspecies can be questioned (and A & E raised questions at the time of their proposal), they remain valid as of now. I have seen nothing that seriously challenges the distribution suggested in E & A, but that may be because most studies do not deal with subspecific identification.
EntomanSep 29, 2011 20:26 0025-0010

Northern California

Topics started: 55
Replies made:  783
Roger - Good catch! I just assumed the distribution records were accurate as they confirmed Usinger, which (until Lloyd's last post) I assumed were still valid as far as the scientific lit showed (at least regarding CA). Even though I've suspected its deficiencies for years regarding this genus, it is the only post '70's book I'm aware of that keys California Drunella to sub-species (by translation).

Lloyd - thanks again for the info. You can tell by my questions I was operating a little on memory (very dangerous).;)
According to Allen & Edmunds, you have no more of a subspecies mix than WA, just a different one.

For clarification, the statement that prompted this response was an assumtion that Usinger was deficient by recognizing only a single sub-species, not a comparison with WA distribution.
Coupled with the taxonomic changes that have occurred since this paper was published?
No. The only significant taxonomic change to the D. grandis subspecies proposed in Allen & Edmunds has been the elevation of the subgenus Drunella to genus status.

I seem to remember at least a half dozen or so sub-species spread out between grandis and obsolete glacialis recognized at least as late as the mid-70's. Did the list expand and contract again after A & E, or (even more confusing) are they older than A & E? This all had to happen somewhere in the timeline running between the benchmarks Needham, Allen, and McCafferty (with Usinger in the middle). What am I missing here?

Regards,

Kurt
Entoman
TaxonSep 29, 2011 20:58 0025-0011

WA, USA

Topics started: 127
Replies made:  623
Lloyd-

Now that you have graciously pointed out a distribution map for the Drunella grandis subspecies, I will make the appropriate subspecies distribution corrections.
Done. Thanks, Lloyd.


Roger Rohrbeck
TaxonSep 29, 2011 22:23 0025-0012

WA, USA

Topics started: 127
Replies made:  623
Hi Guys-

Based on the provided distribution map for Drunella grandis subspecies, this is probably Drunella grandis flavitincta.


Roger Rohrbeck
EntomanSep 30, 2011 00:26 0025-0013

Northern California

Topics started: 55
Replies made:  783
This is great for reference, Roger. I thought it looked a little different, but chalked it up to being immature. Perhaps after more study (staring) of (at) it...

Regards,
Kurt

Entoman
GONZOSep 30, 2011 06:23 0025-0014

"Bear Swamp," PA

Topics started: 4
Replies made:  163
I seem to remember at least a half dozen or so sub-species spread out between grandis and obsolete glacialis recognized at least as late as the mid-70's. Did the list expand and contract again after A & E, or (even more confusing) are they older than A & E? This all had to happen somewhere in the timeline running between the benchmarks Needham, Allen, and McCafferty (with Usinger in the middle). What am I missing here?
The synonymies in A & E are the same as in the current Mayfly Central listing. They did not expand or contract after A & E. I can only guess that Day's 1956 contribution to Usinger was not updated in subsequent editions. (Does your edition mention Ephemerella proserpina?)

BTW, on the higher classification, Needham proposed the genus Drunella in 1905, reduced it to subgeneric status in 1927, and it was re-elevated by Allen in 1980.
EntomanSep 30, 2011 14:46 0025-0015

Northern California

Topics started: 55
Replies made:  783
Hi Lloyd -
I can only guess that Day's 1956 contribution to Usinger was not updated in subsequent editions. (Does your edition mention Ephemerella proserpina?)

Ah.. Thanks for the question. It was the clue that helped me sort this out.

My edition was published in 1973 and I purchased it around '74 or early '75 if I remember correctly. At the time it was still a textbook used in the UC system at the very least. Based on its description as a printing (as opposed to a revision) and the lack of editing references, I assume it wasn't revised.

As to proserpena, the answer is yes and no. In the adult species key which is listed first, it isn't referenced. However, in the nymph key it is, but not as a sub-species of either glacialis or grandis, but rather as a separate species. I didn't suspect the connection until you asked the question, and even then only after noticing in a footnote that it was now considered a synonym of E. yosemite, which I remembered as being part of the grandis mix somehow.
The only significant taxonomic change to the D. grandis subspecies proposed in Allen & Edmunds has been the elevation of the subgenus Drunella to genus status.
It was a misconstrual of this statement that contributed to my confusion. I thought you meant that the only change proposed by A & E was the elevation of Drunella. My bad...

For my own edification, here is the taxonomic chain and what I think A & E did:

1. glacialis as a valid species name was made (or confirmed as) obsolete.
2. E. glacialis carsona became (or confirmed as) E. grandis grandis
3. E. glacialis glacialis and the separate species E. proserpina and its synonym E. yosemite became (or confirmed as) E. grandis ingens
4. E. grandis became (or confirmed as) the new subspecies E. grandis flavincta
5. In 1980, Allen re-elevated Drunella to genus status which was subsequently accepted by consensus as the new genus that the three grandis sub-species now belong to.
6. All the above remains the status quo.

Item 4 is an assumption on my part based on the presumed existence of the grandis name prior to A & E when flavincta was its only representative. Drunella is not mentioned in Usinger, as the species currently in this genus were referred to as belonging to the ''Fuscata group'' at the time. The species name grandis is also absent in Usinger as flavincta was not known in CA.

''Became (or confirmed as)'' is the phrase I used due to uncertainty on my part over whether all or a portion of the changes were due to proposals by the authors or confirmation of suggested/partially accepted changes by others prior to the publication of their paper. Not that it matters much to the main points of the conversation.

Do I have this about right? Whew...

BTW, great to find out that Usinger remains valid for this genus (at least after translation) as I find the keys very useful.

Regards,

Kurt
Entoman
GONZOSep 30, 2011 16:02 0025-0016

"Bear Swamp," PA

Topics started: 4
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Do I have this about right?
Pretty close. In the early '50s, E. proserpina Traver, E. yosemite Traver, E. glacialis Traver, E. flavitincta McDunnough, E. ingens McDunnough, and E. grandis Eaton were considered to be separate species. In '54, Day synonymized E. yosemite Traver with E. proserpina Traver and had previously proposed E. glacialis carsona ('52). New synonymies in A & E ('62) brought all of these under E. grandis Eaton (by priority) as E. g. grandis Eaton, E. g. ingens McDunnough, and E. g. flavitincta McDunnough and also established these subspecific synonymies: E. g. ingens = E. glacialis Traver and E. proserpina Traver (including E. yosemite Traver). E. g. grandis = E. glacialis carsona Day (though the authors stated that the population in the Carson River, from which Day's specimen came, contains intergrades between E. g. grandis and E. g. ingens).

When it's all said and done, the 1956 info in your 1973 edition of Usinger reflects the same current CA subspecies as indicated in A & E (after translation). You just missed one of the synonyms.

PS--Day probably did not include E. proserpina/yosemite in the adult keys in Usinger because both were identified as nymphs. He mentioned in his 1954 paper that he had reared the male and female adults and would describe them in a future paper, but I lose the trail after that.
EntomanSep 30, 2011 18:52 0025-0017

Northern California

Topics started: 55
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Quite a trail, Lloyd!

Entoman
EntomanSep 30, 2011 20:11 0025-0018

Northern California

Topics started: 55
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Roger -

Reviewing reminded me this was your specimen. Though dorsal photos are difficult for use in determinations with grandis nymph sub-species, good laterals should make it easy, particularly of the pronotum and 8th and 9th segments. Do I sense some possible scope work?

Lloyd - what does A & E say about flavitincta projection and spine patterens? The Usinger keys have clear comments complete with excellent illustrations for ingens and grandis.
He mentioned in his 1954 paper that he had reared the male and female adults and would describe them in a future paper, but I lose the trail after that.
Yeah, some undergrad must have left the lid off the cage, because his contribution to Usinger was published in '56.
... Usinger reflects the same current CA subspecies as indicated in A & E (after translation). You just missed one of the synonyms.
Well, not the first time that's happened. I apologize in advance because I'm sure it won't be the last! That sneaky proserpena nymph was hiding itself in the key silt and didn't hatch into an adult with the rest of the fuscata group.

BTW - the adult keys in Day's contribution aren't as useful because as previously stated, there are none for ingens and flavitincta and they rely on color descriptions of aged specimens rather than taxonomic features for grandis.

Regards,

Kurt
Entoman
GONZOOct 01, 2011 00:17 0025-0019

"Bear Swamp," PA

Topics started: 4
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...what does A & E say about flavitincta projection and spine patterens?
''Head and body tubercles long, thin, and acute''

Basically, the tubercles of D. g. flavitincta should be the longest and sharpest of the three subspecies, and those of D. g. grandis should be short and blunt.

Adults of D. g. flavitincta (as the name suggests) should have forewings suffused with ''dark amber.'' Those of D. g. ingens should show some ''light amber'' suffusion basally in the forewings, and the forewings of D. g. grandis should be hyaline.
EntomanOct 05, 2011 15:13 0025-0020

Northern California

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Thanks Lloyd, Day offers the following information for determining between g. grandis and g. ingens nymphs. Taken together with the info you provided, telling the three apart should be doable with good lateral views.

Pronotal tubercles 3 to a side; anterior pair high and blunt; posterior pair small; dorsal spines of segments 8 & 9 about 40% heavier and longer than those of segments 4 to 7 - g. grandis

Pronotal tubercles 3 to a side; anterior pair heavy and blunt; posterior pair much shorter (translate as minuscule based on the diagrams); dorsal spines of segments 8 & 9 very much enlarged, 2 to 4 times longer than preceding pairs - g. ingens

Regards,

Kurt

Entoman
GONZOOct 05, 2011 16:34 0025-0021

"Bear Swamp," PA

Topics started: 4
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The characters you mention do not agree those in A & E. Here are a few possible reasons for that disagreement:
1. Day's keys are regional keys that describe synonyms.
2. One of those synonyms comes from a population that contains intergrades (as mentioned previously).
3. Characters involving relative length of one set of tubercles to another may not be reliable due to different growth rates (according to A & E).
EntomanOct 05, 2011 17:50 0025-0022

Northern California

Topics started: 55
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Hi Lloyd,

Well, that presents a bit of a problem. Perhaps larger samples since Day have found the older keys unreliable? See may latest post in Flav Vs. Color topic by Flykuni.

Or, maybe I'm making a mistake somehow in the taxonomic history. The species referred to in the keys are actually E. glacialis carsona (g. grandis) and E. proserpina (g. ingens). Maybe some issues with the old glacialis sub-species being missed?

Kurt
Entoman
EntomanOct 05, 2011 18:12 0025-0023

Northern California

Topics started: 55
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Ah! Perhaps you are right. I responded before you added possible reasons. Perhaps also, the keys were created before extensive samples had been taken that have since shown variability greater than expected in the characters chosen at the time for inclusion in the keys? Whatever the reason, this sure doesn't make it any easier.

Kurt
Entoman
GONZOOct 05, 2011 19:07 0025-0024

"Bear Swamp," PA

Topics started: 4
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The distinctions in A & E are not difficult: in general, D. g. flavitincta has long sharp tubercles, D. g. grandis has short blunt tubercles, and D. g. ingens is somewhere inbetween. However, given the unresolved questions that A & E raised, the result of using those characters is probably a somewhat uncertain determination of a somewhat uncertain subspecies.
EntomanOct 05, 2011 20:03 0025-0025

Northern California

Topics started: 55
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Lloyd,

This is the first time Usinger has let me down. Do you think the key may remain valid for CA grandis specimens? I wonder if the same problems are in play with flavilinea and coloradensis? Not that any of this makes much difference from an angling perspective.

BTW, do any eastern Drunella's turn as dark as these critters when ready to molt?

Sorry for three questions in one post.

Regards,

Kurt
Entoman
GONZOOct 05, 2011 21:03 0025-0026

"Bear Swamp," PA

Topics started: 4
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Do you think the key may remain valid for CA grandis specimens?
At the species level, it seems to present no problem other than not fully reflecting the range of variation. It would not be a reliable means of subspecific identification, but I think that some aspects of the subspecific IDs remain open questions. Frankly, I don't really understand why A & E synonymized Day's E. glacialis carsona with D. g. grandis when they say this: ''Day (1954) described Ephemerella glacialis carsona from the Carson River of California from a population which our studies now prove to be intergrades between E. grandis grandis and E. g. ingens.''

I wonder if the same problems are in play with flavilinea and coloradensis?
See my response in that thread.


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