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Mexican Swallowtail – Giant Swallowtail or Thoas Swallowtail?
hi Bugman!
I wrote a few weeks ago after I found a caterpillar I could not identify. I gave it a habitat and let it do it’s thing. I came home to a beautiful swallowtail yesterday! I originially thought it was an ‘orange dog’ caterpillar — but it wasn’t quite the right colors.

Then I found a Mexican website (I live in Tucson Arizona) and was able to see it was some sort of swallowtail larva. I have attached a photo sequence of caterpillar, to chrysallis, to butterfly.

It’s happily fluttering about my yard now, but I think I got some good pics while it was in my care. This time I sent web-ready versions if you want to post them. I’m having trouble determining if it’s Giant Swallowtail or Thoas Swallowtail. See:
and http://www.mariposasmexicanas.com/papilio_heraclides_thoas_autocles.htm
I cannot really determine (even by Googling) if the lower wing red markings are classic of either species since my swallowtail has more red going up the lower wing. Either way, it seemed to be a mexican variety (sandy coloring) of the usual dark brown/white orange dog caterpillar. I love your site! You got me hooked and trying to identify this critter! Thanks!

Hi Adrienne,
Thanks for all the photos and research. According to BugGuide: The Giant Swallowtail is “Distinguished from P. thoas by the larger spots forming in the lower left leg of the X on the front wing. ” Your specimen has small spots on the forewings, so we favor Thoas Swallowtail. Here is just one more link with information.

What's That Bug? does not endorse extermination
Location: Tucson, Arizona

2 Responses to Female Giant Swallowtail

  1. David J. Ferguson says:

    This is a female GIant Swallowtail – Papilio cresphontes. It definitely is not Papilio thoas (which would be very unlikely in Arizona). The two are similar, but the patterns are different, and with practice they are not difficult to tell apart.

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