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August 17, 2020

Apantesis vittata and the self-replicatory nature of misidentifications

I've been meaning to post on this subject for a while, and after once again working to correct misidentifications of Apantesis vittata last night, I figure now is as good a time as any.
First off, some background on this species. Apantesis vittata is a moth found in the southeastern USA. It is replaced to the north by the visually extremely similar Apantesis nais. The main differences between these species are the shape of the male genitalia, visible only by dissection under a microscope. The wing patterns are variable in both species, and there is a lot of overlap, especially in the females. In addition, the very abundant Apantesis phalerata occurs throughout the eastern USA, flying with both vittata and nais.
A typical example of a male A. vittata can be seen here: https://bugguide.net/node/view/1492279/bgimage
A typical example of a male A. nais can be seen here: https://bugguide.net/node/view/1755934/bgimage
The trend is for vittata to have reduced forewing markings and spots on the collar of the thorax, which nais lacks. However, this is only a trend, and male nais frequently have these markings, as is the case here: https://bugguide.net/node/view/1755935/bgimage
Here is a typical male of A. phalerata: https://bugguide.net/node/view/10566
Note that the hindwings have a broken black border, are pink at the base, and fade to yellow toward the outer edge. Females have pink hindwings without the yellow portion.
Females of all three of these species have reduced forewing markings and spots on the collar, such as this individual: https://bugguide.net/node/view/633456/bgimage
Based on specimens examined and dissected, A. vittata appears to be restricted to the Gulf Coast and the Atlantic Coast north to the Carolinas. Here is a summary of the species group by @neoarctia, an expert on the Apantesis: https://tinyurl.com/y6ksj78o

Now, here is the major problem with this group. Check the records on iNaturalist, BAMONA, and Moth Photographers Group, and you'll see dozens upon dozens of records of Apantesis vittata from all over the eastern USA, as far north as New England. Could all those records be wrong? How could something like that happen? Well, the answer is, yes, they're all wrong, and how it got to this point is the main reason I'm making this post.
I think it all goes back to BugGuide, one of the earliest sites with user-submitted records of moths. Prior to 2015, there were many photos of Apantesis vittata posted from all over the eastern United States. The difference listed on the page there for A. vittata vs. A. nais was A. vittata's "reduced forewing markings". Of course, females of both species have "reduced forewing markings" compared to the males, and what was actually happening on that page was male nais were being posted as "nais" while female nais were being posted as "vittata". I moved all these female nais off the vittata page in 2015, but unfortunately, the records had already made their way to Moth Photographers Group, where the dots remain to this day, suggesting that vittata occurs in places like Massachusetts, Iowa, Illinois, New York, etc. (which is wrong). Wikipedia just copies its range information from Moth Photographers Group, so it now indicates a very broad range for the species as well.
Meanwhile, with BugGuide, MPG, and Wikipedia indicating that vittata occurs much farther north than reality, Butterflies and Moths of North America (BAMONA) started accepting records of vittata from all over the place, despite some of them being dead-ringers for other species. For example, the main thumbnail on the BAMONA page here: https://www.butterfliesandmoths.org/species/Apantesis-vittata?page=2 has already been corrected to A. nais by an expert and moved to the A. nais page on BugGuide, here: https://bugguide.net/node/view/782932
In fact, nearly all the BAMONA "vittata" photos are unidentifiable at best, and clearly wrong at worst.
Check out the hindwing on this one, clearly phalerata or carlotta, and not nais or vittata: https://www.butterfliesandmoths.org/sighting_details/498894
Here's one that's clearly nais: https://www.butterfliesandmoths.org/sighting_details/902351
Another nais: https://www.butterfliesandmoths.org/sighting_details/527619
Classic carlotta: https://www.butterfliesandmoths.org/sighting_details/507248
And, as with the way they were once sorted on BugGuide, you'll notice from the thinner antennae that most of the ones on BAMONA are just females with the "reduced forewing markings" seen on females of all these species.
Of course, records "verified by BAMONA" make their way onto other websites. For example, vittata likely doesn't occur in Maryland, but check out all the classic phalerata photos listed as vittata here: https://www.marylandbiodiversity.com/viewSpecies.php?species=2496
iNaturalist now gets so many photos submitted under the name vittata that the AI suggests it left and right, even claiming "seen nearby" in places where the species doesn't exist.
So now here we are, in 2020, with all the standard online resources for moths showing a vastly over-representative range for Apantesis vittata, and the posts assigned this species name on iNaturalist popping up faster than anyone can correct them. Part of the problem is that most of the photos on iNat are just not identifiable, and people often get annoyed when you throw things back to the genus level after they think they know what species it is. But a big part of the problem though is that telling someone "vittata isn't found in your area" is a hard sell when they can look at any moth website and see apparent evidence to the contrary. A. vittata certainly might occur in places where it's not yet been recorded, but in the absence of a dissected specimen, it's hard to justify a claim of a range extension based on a photo that might be one of several species.
I don't know what the solution is to this issue, and I'm sure this isn't the only species group where this is an issue. But as someone interested in accuracy of species records, this situation is just overwhelming. Every time I decide to work through identifying these, there are just so many "vittata" to go through, and nearly all of them are either definitely wrong or probably wrong.
I'm curious what others think about this sort of problem. Is this just a feature of crowd-sourcing photo records of things that can't always be identified from photos? Is there a feature that could be added to iNat to make it harder to submit records outside the known range of a species without being really sure of your ID? All thoughts appreciated.

Posted on August 17, 2020 15:54 by paul_dennehy paul_dennehy | 12 comments | Leave a comment

March 14, 2019

Confusing Yellow Pyraustines Demystified

The purpose of this post is to demystify the “confusing yellow Crambids” in the subfamily Pyrausinae in the United States and Canada. This is a group of moths with some difficult-to-identify species, but many are identifiable based on photos alone if you know what to look for. The species and genera discussed here are:
Hahncappsia spp
Helvibotys spp
Neohelvibotys spp
Crocidophora tuberculalis
Ecpyrrhorrhoe puralis
Paracorsia repandalis
Anania labeculalis
The first three genera are closely related and contain some extremely similar species. The last three species are superficially similar to the species in those genera, and appear to be commonly confused with them online.
Virtually every online moth ID platform has a history of major misidentifications of all these species. BugGuide was a mess until I sorted through their photos in 2017, MPG had lots of misidentifications until it was updated in 2017, and BAMONA still has quite a few misidentifications in this group as of March 2019. The first thing to look at when trying to place these species is the st line on the forewing. The following characteristics can help start the ID process:
Hahncappsia spp: Most have an st line present, but it can be faint. When present, it is always straight, not curved to parallel the terminal edge of the forewing. H. fordi and H. alpinensis, both species found exclusively in the Southwest, are very plain and lack st lines entirely, making them look more like Helvibotys spp than like other Hahncappsia.
Helvibotys spp: no st line present
Neohelvibotys spp: no st line present
Crocidophora tuberculalis: A native species to most of the East with a bold, thick, dark st line that is curved so it parallels the terminal edge of the forewing. This should make this species unmistakable. The males of this species also have a scaleless crinkled fovea on the forewing, which isn’t seen in any other species treated here. Here’s a male with the crinkled fovea: https://www.inaturalist.org/observations/18384692 And a female without it: https://www.inaturalist.org/observations/20497923
Ecpyrrhorrhoe puralis: a large bright yellow species introduced in the Southeast with faint markings overall, the st line being curved when present, but often not visible. Here’s a well-marked one: https://www.inaturalist.org/observations/4041567 And a poorly marked one: https://www.inaturalist.org/observations/817257
Paracorsia repandalis: a dull species introduced in the Northeast and upper Midwest with a curved st line, and thick smooth pm and am lines. Here’s a typical one: https://www.inaturalist.org/observations/12281430
Anania labeculalis: a southwestern species with a faint, thin, wavy st line. The lines on this species are all generally very thin and quite dark, and it can be easily separated from Hahncappsia in the area by its complete PM line on the hindwing, reaching the inner margin. Look at the visible pm line on the hindwing here; no way this should be mistaken for a Hahncappsia: https://www.inaturalist.org/observations/868592
Once you’ve eliminated A. labeculalis, E. puralis, P. repandalis, and C. tuberculalis for your moth, there are a few “easy” to identify Hahncappsia and Helvibotys you can check.
Distinctive species:
Hahncappsia coloradensis: this is a big white species of the interior mountain west and western plains, with dark brown scaling near the costa and around the reniform and orbicular spots, which looks like this: https://www.inaturalist.org/observations/16683451
Hahncappsia mellinialis: This species is bigger than any other treated here, is brown, is only found in mountains in Arizona and New Mexico (maybe west TX too?), and is more likely to be confused with an Ostrinia than a Hahncappsia. Here’s a typical specimen: https://bugguide.net/node/view/1299446/bgimage
Helvibotys pucilla, Helvibotys freemani, and Helvibotys subcostalis: these look nothing like any of the other species treated here, and can be viewed on MPG.
If you don’t have one of these “distinctive” species, placing your moth to genus gets a little trickier. This is generally what I look for:
Hahncappsia: Usually have more wavy pm lines on the FW than Helvibotys and Neohelvibotys. Other than alpinensis and fordi, usually have at least a trace of an st line on the forewing. Here are some typical Hahncappsia specimens: https://www.inaturalist.org/observations/9457573 https://www.inaturalist.org/observations/14577667
Helvibotys and Neohelvibotys: usually have smooth and very bold pm lines on the FW, and never have an st line. Here’s a typical specimen: https://www.inaturalist.org/observations/14137388
Hahncappsia alpinensis and fordi are two “non-typical” Hahncappsia that look like this: https://www.inaturalist.org/observations/19012350 The forewings look more like Helvibotys than Hahncappsia, but note the almost complete lack of markings on the hindwings, and note how faint the markings are compared to a real Helvibotys/Neohelvibotys like this: https://www.inaturalist.org/observations/14845820. H. alpinensis and fordi are best separated by genitalia where they both occur, from Arizona to west Texas. In Southern California and Nevada, only fordi occurs, and in most of Texas, only alpinensis occurs, so in many cases they can be ID’d by range.
If you have a “typical Hahncappsia”, these are your options:
In the East, you could have pergilvalis, mancalis, marculenta, neomarculenta, or neobliteralis. In the Southwest, you could have pergilvalis, mancalis, huachucalis, jaralis, pseudobliteralis, or cochisensis. In peninsular Florida, you likely have H. ramsdenalis: http://v3.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxid=341792
Hahncappsia mancalis: This species has the boldest and most complete st line of any of the typical Hahncappsia species. It also tends to be more tan in color (less yellow) compared to the other options. Here’s a typical example: https://www.inaturalist.org/observations/14680897
Hahncappsia pergilvalis: This species is generally paler in its base color than the others it occurs with, and its st line is usually splotchy and broken in the middle, like this: https://www.inaturalist.org/observations/16683448
Hahncappsia marculenta/neomarculenta/neobliteralis: this is the trio of eastern yellow species that is the most difficult to separate in photos. Marculenta is by far the commonest of the three, but the others are equally as widespread. Here is a typical example: https://www.inaturalist.org/observations/10186526 This species group is only differentiable based on genitalia, and specimens that have not been dissected should never be identified to the species level.
Hahncappsia huachucalis: This species is abundant in the mountains of southeastern Arizona, but doesn’t occur outside that region in the US. It’s a pretty spectacular-looking rusty brown species that isn’t easily mistaken for others in the genus in good condition: https://www.inaturalist.org/observations/10869666 It’s the most common Hahncappsia in the Chiricahua Mountains.
Hahncappsia jaralis/pseudobliteralis: This pair is the southwestern equivalent of the eastern marculenta/neomarculenta/neobliteralis group, and is also best separated based on dissection. Here is one of each that I dissected: https://bugguide.net/node/view/1457763/bgimage and https://bugguide.net/node/view/1457757/bgimage
Hahncappsia cochisensis: This is the only Hahncappsia species in the US that I haven’t personally encountered, so I can’t make many generalizations about it. It appears to be a pale yellow species with white hindwings found in southeastern Arizona: http://v3.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxid=287890 The plain white hindwings seem to be diagnostic.
If you have a typical Helvibotys/Neohelvibotys, then consider the following options:
In most of the East, if your moth has a dark terminal band, like this: https://bugguide.net/node/view/1422376/bgimage then you have N. neohelvialis. If your moth lacks this, and is a bit smaller, then you likely have H. helvialis, shown here: https://bugguide.net/node/view/528994/bgimage
In the Southwest, then the large ones with the dark terminal band are N. arizonensis, shown here: https://bugguide.net/node/view/1441697/bgimage, while the small ones without it are likely to be H. pseudohelvialis: https://bugguide.net/node/view/1457768/bgimage
The only other species that throws a wrench in things is N. polingi, a Neohelvibotys that lacks the dark terminal band like a Helvibotys and is found from Florida west through Texas (possibly also SE Arizona?). If you’re in the Deep South, you’ll likely need to dissect your Helvibotys-looking specimens to distinguish between the two Helvibotys species and N. polingi. Here’s a N. polingi specimen: https://www.inaturalist.org/observations/6809500
Hopefully this post provides enough information to determine which of these yellow Pyraustines are identifiable from photos and which are not. There are a lot of species involved in this group, but most can be identified if you know what to look for.

Posted on March 14, 2019 02:42 by paul_dennehy paul_dennehy | 5 comments | Leave a comment

May 07, 2018

The Dubious Records of the Dubious Tiger Moth (Spilosoma dubia)

Of all the species of Spilosoma in the United States and Canada, none seems to be more misunderstood in online records than Spilosoma dubia. Between BugGuide, iNaturalist, Moth Photographers Group, and BAMONA, I have seen dozens of misidentified photos labeled as S. dubia, and about one real S. dubia for every ten misidentifications. For example, as of May 2018, the BAMONA page for S. dubia features photo records of Norape ovina, Hyphantria cunea, Spilosoma congrua, and Artace cribrarius, and one or two photos that may be S. dubia, but not one definitive dubia photo in the bunch.

Why is this species so often misidentified? I’d say one main reason is lack of understanding of the species’ range and abundance. S. dubia has two disjunct populations in North America. One population occurs in the Canadian Zone in boreal forest from Alberta east to New England and the Maritime Provinces. This population occurs as far south as northern Pennsylvania, where it is quite rare. The second population occurs along the Gulf Coast, from eastern Texas through Florida, and northward along the Atlantic coastal plain to North Carolina. The species is therefore absent from most of the eastern United States, occurring only in the far northern and far southern parts of the region. (Dale Schweitzer, personal communication). I’ve personally collected the species in coastal North Carolina and the Upper Peninsula of Michigan, and the series of specimens from the two populations are indistinguishable to my eye. Unfortunately, many photos of similar white moths with black spots were posted under “Spilosoma dubia” on BugGuide throughout the 2000s, and those records made their way onto the Moth Photographers Group maps at the time. That led people to believe that this was a common and widespread eastern species, which led to numerous misidentifications on BAMONA, and ultimately to a range map in the new Peterson Guide to Northeastern Moths that shows the species occurring throughout the eastern US. Now that this over-inclusive range has become so widely accepted by moth photographers, photos are frequently posted to iNaturalist identified as S. dubia that are 500+ miles out of range.

So, how does one actually identify a “real” Spilosoma dubia? Well, there are five eastern species to consider before arriving at a definitive ID of “S. dubia”, and seeing the abdomen of the specimen is essential to making an ID. If you just have a photo of the moth with its wings folded up, you probably won’t get a definitive ID.

  1. Spilosoma congrua: forewings range from pure white to moderately speckled with black. The abdomen is pure white. Front legs are yellow-orange
  2. Spilosoma latipennis: forewings are almost always pure, silky white. The abdomen is pure white. Front legs are bright pink (hence the common name).
  3. Spilosoma virginica: forewings are pure white or have a few black spots. The abdomen has bright yellow-orange sides and a row of large black spots down the back of it. Without seeing the abdomen, these could be mistaken for S. latipennis or a lightly marked S. congrua.
  4. Hyphantria cunea: forewings range from pure white to very heavily covered in black. This species is generally noticeably smaller than the Spilosoma species. The abdomen is white on the sides (never any yellow), but usually has a row of small black spots along the top of the abdomen. There is also a difference in the spurs on the front legs, which is usually not visible in photos.
  5. Spilosoma dubia: forewings are almost always moderately speckled in black, basically identical to a well-marked S. congrua. However, the abdomen has yellow along the sides and black spots along the top, like S. virginica. There are long white scales that overlay the yellow section of the abdomen though, causing the yellow to not stand out or be as bright as in S. virginica. I often describe S. dubia as a “dirty” version of S. virginica for this reason. Those white scales rub off over time, leaving the yellow more noticeable. For comparison, here is a S. dubia with the white scales on the abdomen worn off, making the yellow stand out more: http://v3.boldsystems.org/pics/_w300/LNC/06-NCCC-733%2B1147097706.jpg and here is a S. dubia with the white scales still intact, obscuring the yellow coloring: http://v3.boldsystems.org/pics/_w300/LNC/06-NCCC-732%2B1147097682.jpg The yellow is still visible in both specimens though. The front legs of S. dubia are yellow, just like most of the other species (except S. latipennis).

So essentially, if you are just going by forewing pattern, S. dubia is identical to a well-marked S. congrua, and extremely similar to a moderately marked H. cunea, and could easily be mistaken for either of those species. Only by examining the abdomen can you see the differences that separate these three. Somehow, it seems to have become common practice online to identify any Spilosomina specimen with moderately-to-heavily speckled wings as “S. dubia”, despite there being two other much more likely identifications for such specimens. If you are outside the two known ranges of S. dubia, it’s almost certain you have S. congrua or H. cunea, and even within its range, it’s usually not as common as the other two options.

In conclusion, there are a handful of definite S. dubia photo records online, which clearly show the dirty yellow on the abdomen, and all are from Texas-coastal North Carolina, or from the far northern Canadian Zone. There are many more supposed S. dubia records online from other parts of the United States, and not a single one of them shows the abdomen to confirm the ID. These records should not be trusted unless more information can be supplied. If you live in the area outside where S. dubia is known to occur, and you would like to find a specimen to expand the species’ known range, then be sure you’re getting photos of the top and sides of the abdomen when you encounter possible dubia specimens. Otherwise, your records are likely to remain “ddubious” forever.

Posted on May 07, 2018 16:09 by paul_dennehy paul_dennehy | 2 comments | Leave a comment

April 20, 2018

Zale lunata vs. Zale minerea

Zale lunata and Zale minerea are common widespread moths in the United States and Canada, and the two are often confused. Both have multiple phenotypes, and the variation in coloration within each species is far greater than color differences between them. Here is a comparison of the forms from the Northeast:

https://tinyurl.com/y9oldr8t

You'll notice that lunata is consistently larger than minerea, but this doesn't help much when identifying photos of individual moths. The palps are also different in length, but the easiest way to tell them apart is by looking for the "double lobe" in the PM line which is present in lunata but absent in minerea. Here's an image showing this difference highlighted:

https://tinyurl.com/y73jmv3e

Of course, there are dozens of other Zales out there too, so one can't rule out every other Zale species with this rule. In particular, galbanata looks like a paler version of minerea in some of its forms, and it often gets confused with minerea (though you should never confuse it with lunata, as it lacks the bilobed PM line.) But if you're fairly certain you've got a minerea/lunata, this is a pretty consistent way to figure which one it is.

Posted on April 20, 2018 21:36 by paul_dennehy paul_dennehy | 5 comments | Leave a comment

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