How do you differentiate P.cresphontes from P.thoas

[lordpandarus]

This is supposed to be P. cresphontes from Mexico .I have a P. thoas thoas from Brasil that has nearly identical markings only it's much larger and more elongate forewongs. Is that the difference?

[livingplanet3]

Take a look at -

iainpetrie.typepad.com/the_four_ages_of_sand/2011/08/how-can-you-tell-a-king-swallowtailthoas-swallowtail-papilio-thoas-from-a-giant-swallowtail-papilio-.html

www.neotropicalbutterflies.com/Site%20Revision/Pages/Swallowtail%20pages/Heraclides_thoas.html

bugguide.net/node/view/157023

[lordpandarus]

I'm still not sure , there is a faint fourth spot on mine .

[livingplanet3]

According to the BugGuide link:

"NOTE: The three or four submarginal spots mentioned in the key above are relatively large spots. In both species there are sometimes more tiny spots in the same position in cells above these (don't count those)".

Yes - it can still be rather difficult to distinguish between the two species, even with the above detail.

I suspect that your specimen is probably cresphontes, though. It's been my observation that on average, the tails in thoas are slightly more elongate (although, as with the markings, there is some variation in that, too).

[lordpandarus]

I guess I'll go with cresphontes!

[eurytides]

I think thoas. The forewing spots in cells M2, M3, Cu1 all typical thoas. Hindwing submarginal yellow spots - looking at the crescent shape of the innermost two spots, this would also go with thoas.

[lordpandarus]

well, here a pic besides P. thoas thoas from Brasil. but I'm not sure what P.thoas from mexico looks like for proper comparison

[lordpandarus]

Feb 14, 2021 18:27:30 GMT -8 eurytides said:

I think thoas. The forewing spots in cells M2, M3, Cu1 all typical thoas. Hindwing submarginal yellow spots - looking at the crescent shape of the innermost two spots, this would also go with thoas.

oh no! more confusion!

[eurytides]

No confusion. Both looks good for thoas. The M3 and Cu1 spots are rectangular in thoas and more oval in cresphontes. The M2 and M3 spots are nearly equal in size for thoas, not so for cresphontes. Both specimens you show look like thoas to me.

[eurytides]

Google some pictures from reputable sources and compare these characteristics for the two taxa. The differences are hard to notice, but once you do notice them, then it doesn’t seem as subtle.

[lordpandarus]

oh well, I was kind of hoping it was cresphontes because I didn't have that species!

[eurytides]

Cresphontes is pretty common. I don’t expect you would have too much trouble finding it on the market.

[Paul K]

I agree it is P.thoas. Looks exactly the same as ssp.autocles I collected in Costa Rica. I suppose it is same subspecies.

[Adam Cotton]

This specimen is P. thoas autocles as eurytides and Paul K say.

In any case if it comes from Mexico it can't be Papilio cresphontes, it is either P. rumiko or P. thoas autocles. Papilio cresphontes does not occur in Mexico.

Here are a couple of jpeg figures extracted from the original description of Papilio rumiko Shiraiwa & Grishin, 2014 to show the difference between rumiko and cresphontes and the distribution of the two species.





Citation:
Shiraiwa K, Cong Q, Grishin NV (2014) A new Heraclides swallowtail (Lepidoptera, Papilionidae) from North America is recognized by the pattern on its neck. ZooKeys 468: 85-135. doi.org/10.3897/zookeys.468.8565

Unfortunately for lordpandarus the more obvious differences between those two species are on the underside.

Adam.

[eurytides]

Adam, does thoas use Rutaceae? There seems be much confusion about this on the internet but I can’t locate an actual paper to clarify the issue either way. On the one hand, thoas is closely related to cresphontes so Rutaceae use seems plausible at least. However, other sources say thoas only uses Piperaceae. This might also be plausible since the taxa are easily misidentified. Do you have any insights?