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Photo#197816
Ctenucha - Ctenucha multifaria

Ctenucha - Ctenucha multifaria
Garrapata State Park, Monterey County, California, USA
July 4, 2008
Size: 2.5-3cm long
Lots of these flying around during the day. Some kind of tiger moth (Arctiidae)?

Images of this individual: tag all
Ctenucha - Ctenucha multifaria Tiger moth? - Ctenucha multifaria - male - female Tiger moth? - Ctenucha multifaria

Moved

 
Ctenucha
I'm not necessarily disagreeing with the move, but I'm curious what criteria you used to determine the ID? Even Dr. Schmidt, who is an expert in Arctids, weighed in on this one (see below) and determined a species ID was not possible. However, if there's any new data and criteria used for ID, it would be very helpful to post here for reference.

 
Criteria used to move various posts within this complex, and why
Just so folks know, below are the criteria I used when I moved images within this "species complex":

1) If the images clearly displayed "white margins at the wing tips only" AND the patagia (definition here) were clearly "red with blue/black (interior) spots"...then I moved them to the C. rubroscapus node;

2) If the images clearly displayed "white margins along the entire wing margin" AND the patagia were "entirely blue/black"...then I moved them to the C. multifaria node;

3) Otherwise (e.g. if wing tips were white and entire patagia blue/black, or the entire wing margins white and patagia red-spotted, or some intermediate mix) I placed them at the species complex node.

I don't mean to imply that's the only way to go...but it seemed apropos to me given the traditional circumscriptions of each "species". If other editors would like to replace that scheme by another reasonable approach, that's fine with me!

To learn "why" I moved this post (and some others) within the "rubroscapus/multifaria" complex, see my "Two species or one" comment, further down in the comments thread here.

Moved
Moved from Ctenucha.

Ctenucha
I'm pretty sure this is Ctenucha multifaria. It's very close to rubroscapus, but differs by having an all black collar (verses red w/ black spots) and the white edging along the costal margin.

 
It looks as though only the oldest
of the images in the guide under rubroscapus actually has the red collar with the black spots, and almost none of them in either group has the white edging. You may need to visit the images already in the guide, Jason, and see if some of them need moving. All but one may be multifaria.

 
Ctenucha sp
The description I gave above is based on Holland. If I'm not mistaken, I believe I read somewhere that the primary distinction is the white costal border. That is to say that the "all black" verses "red/orange with black spots" on the patagia may be variable in rubroscapus - in that rubroscapus may have both, but multifaria will only have an all black collar, and of the two, only multifaria will have the white costal border. I think I may consult a couple of people on this to see if any more recent info on these two has been published that I'm not aware of.

 
Links for Holland reference
Here's a link to the text of the Holland reference Jason mentioned above, and to the Plate XIII that Holland refers to (although the figures 19 and 22 for multifaria and rubroscapus therein don't appear to help much.)

As Jason indicated in his earlier comment, Holland stated that in multifaria: "the costal margin of the primaries is narrowly edged with white". Holland also stated that in multifaria "the wings are lighter in color" and "the collar is black, not orange spotted with black as in C. rubroscapus".

 
Holland
The problem with Holland's description and plate is that it's outdated (it's 100 years old after all) and hasn't been supported by the recent data, hence the confusion between the two species and the possible determination that they may even be a single geographically variable species (my understanding from the last info I had was that the genetic variance between the two species is barely even great enough to qualify them as a subspecific relationship, and supports the hypothesis that they may be one and the same, with clinal variation between populations in different geographic regions - I'll try to find out more on this).

But unless there's any new data in which the species can be distinguished by appearance alone, then the move to species level isn't justified - it would be best to leave at the species complex level.

 
Two species or one
Hi Jason. I was researching & writing other comments (including the one below) when you posted your two 7/21/14 comments above...apologies for any confusion or misunderstanding that may have arisen from that (or, for later readers, from the mixed-up order of my comments in the thread here).

When I posted my recent image, it conformed perfectly to the description of C. rubroscapus and I couldn't find any evidence that Chris Schmidt's suspicion that the two species were actually the same had been resolved and published. And since Powell & Opler was published after your 2008 comment above, as was Merrill Peterson's Pacific Northwest Moths website...and both still referred to P. rubroscapus...I figured the issue hadn't been officially resolved (since P. multifaria was published earlier, and thus would presumably become the name for the single "lumped" species).

So it seemed appropriate to place images that clearly conformed to the currently published taxonomy, to help clarify the issues involved, while leaving them both under the "No taxon" rubroscapus/multifaria node so that people would know there is uncertainty here, and there would be a place to move all the images when the issue is officially resolved (presuming they are lumped). In situations like this, even if the species are eventually lumped, I find it helpful to be able to see the extremes of the clinal variations that were earlier used to separate previously recognized taxa.

Hope that makes sense, it seemed to to me. But if not, and folks have other ideas, I'm sure we can work it out.

 
I should've known :-)
I heard back from Chris Schmidt today, and the bottom line is that all the characteristics mentioned are not consistent enough to be reliable. And he states they may actually be variations of one species. DNA analysis is forthcoming to determine as such. Here is what Chris stated:

"Hi Jason - the taxonomy of this group needs some work; I suspect rubroscapus and multifaria are slight geographic variants of the same species. The supposed diagnostic diff's don't hold up in series of specimens (even from the same place), since the extent of the black on the patagia and white on the costa are both variable. I can find no diff's to reliably separate the two, although I suspect there would be subtle 'average' diff's between topotypical series."

Given that they are not distinguishable by appearance and cover the same general distribution, it may be best to lump rubroscapus/multifaria into a temporary species complex until the mtDNA analysis is presented and the systematics worked out.

 
Any news on results of the mtDNA analysis?
I'm very curious if the status of C. rubroscapus and C. multifaria has been resolved and officially published yet?

I just posted an image of mine that would go to C. rubroscapus under the old Holland circumscription, and which appears to be in accord with the fairly recent (i.e. after 2008) MPG and Pacific Northwest Moths web pages for that species, as well as with the discussion in Powell & Opler(1)(2009), which states that C. rubrocapus "has a narrowly white tipped smoky black FW and HW"...but makes no mention of P. multifaria. (If they were now being treated as a single species, I believe multifaria would have precendence.)

I don't have any special knowledge on the current standing of the circumscription of the two species in question here, and it seems plausible to me that they may indeed be variants of a single species, as Chris Schmidt said he suspected in his 2008 remarks. For instance, the BugGuide post below seems in accord with Chris's ideas:



However, from the MPG, Pacific Northwest Moths, and Powell & Opler references, it seems to me this issue hasn't been officially resolved yet. (If they were now being treated as a single species, I believe the epithet multifaria would have precedence, and rubroscapus would not be being used.) So I tentatively moved some images that clearly conformed to one or the other of the two previously described "species"...leaving all the others (and both species nodes) under the "No taxon" rubroscapus/multifaria node for now.

 
Not sure
I'm not sure if any new data on the genetic analysis has been published (or even completed). And what I mentioned before was the last info I had on the two. It definitely hasn't been resolved yet. The MPG and PNW Moths pages aren't primary sources, but even the Lafontaine/Schmidt 2010 checklist still lists the two species separately, so if any revision is forthcoming, I haven't yet heard of it. It kind of leaves us in limbo, where the current published data has them separate, yet gives us no concrete diagnostic criteria to distinguish them with certainty.

I see now how you have the page set up, with the two species nodes under the species complex, so I think that should be fine. I often go back and forth on the value of trying to differentiate species in a complex based on photos, or just leaving them lumped. But at least the way you have it, we're still in effect able to use Holland's description as a useful guide to at least gather like with like.

 
DNA vs. Rearing and Crossing Experiments
I'm glad you see now how I've set things up on the rubroscapus/multifaria BugGuide node...I also made substantial additions to the info page to help clarify the issues here.

Regarding resolution of species delimitations in situations like this, I'd generally find evidence based on a well-designed set of rearing and crossing experiments to be preferable to the typical molecular/DNA approach.

I'm still quite leery of many of the (significant) taxomomic rearrangements that molecular methods have wrought. There are usually too many "black box" steps in the molecular approach (i.e. in choosing the markers, processing the material, generating cladograms, etc.)...where modern taxonomists often simply plug data into a long sequence of hugely complicated and nuanced chemistry protocols and software programs and then churn out results. And often such results are published by multiple authors, many of whom are (current or) recent graduate students trying to create a publication list, and who don't necessarily have the substantial depth of understanding (or motivation or incentive) necessary to critically and rigorously question and reject their results in accordance with appropriately high error tolerance thresholds.

Moreover, very few people thoroughly read and/or can critically respond and help refine the results in such papers...they're mostly accepted "de facto" as the latest hi-tech taxonomic pronouncements from on high. In many cases, I question whether the emperor has no clothes? (Or at least fairly skimpy ones :-)

Has the head and shoulders
of one of the red Ctenuchas in the guide here, but we're not sure about the white wing edge.

 
Wing stripe
It does look similar to Ctenucha rubroscapus, but both sexes had a distinctive white stripe all the way along the wing edge.

 
Could we have a new species for the guide here?
Ctenucha brunnea is listed for CA and has the white edge to its wing, though the top of the wings looks a lot more brown than this in images I've googled. See here. Did you get any shots from above?

Another possibility is that the white edge only shows on C. rubroscapus at this angle. Compare this image in the guide, which does appear to have the white stripe:


 
More images
I added two more images. The color is definitely dark; much darker than those Ctenucha brunnea pictures.

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