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Journal archives for August 2020

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

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