Comparison - Giant & Ornythion Swallowtails

I often confuse these two butterflies as at first glance they seem the same. When I'm out in the field it's hard to tell them apart if they are flitting around so a quick reference point for me is to look at the tails...the Ornythion does not have yellow spots on the tail. Figured I'd post some dorsal and ventral photos to show them.

There are other differences - compare the forewing bottom row of yellow marks as well as the hindwing yellow marks - on the Ornythion they are more chevron like. Also the yellow band is a bit wider on the Ornythion.

~ Cat

This message was edited Jun 15, 2007 10:44 PM

Ventral view...kind of hard to tell them apart!!!

The female is easier to tell apart as this is the dark form.

Dorsal and ventral view of Ornythion Swallowtail female.

Cat - Awesome short lesson on IDing and telling the difference between these to Swallowtails! Thanks!

Which one do you see most often in your area?

I don't get the Ornythion Swallowtail here at all and I don't think it is found anywhere in Florida. Am I correct?

Giant Swallowtails are here in abundance...and with so many flying around it's easy to think...ehhh, it's just another GST.

Ornythions are somewhat rare out here but we do see them. A fellow butterflier photographed some puddling in the next county over.

I never thought much about them until I found late instar caterpillar that looked the same as a GST cat but there was just something about it...a more pronounced coloring with a bluish/purple hue to the markings and more orange than white. GSTs are quite common so I don't usually raise them...I pretty much leave Mother Nature to do it but on a whim I gathered all the cats from the citrus tree and they pupated back in October. Several emerged timely and I set them free but didn't pay attention to them as again, I thought ehhhh...they're just GSTs. It wasn't until February and March when the ones that overwintered. Three turned out to be Ornythions. When the first emerged I took a photo just for grins since I'd been baby sitting it so long. Released it and uploaded the photos on the computer. It wasn't until then that I realized it was different. When the others remaining emerged I knew what to look for :o) DUHHHH!!!

Then I found eggs on my rue a couple of months ago and thought...ehhhh, GSTs again...but I raised them anyway. Several were GSTs and two were Ornythions :o)

Haven't had a female though...and all the ones I've released were males.

Am sure they are more Ornythions out there than we think...but because the males look so much like GSTs we overlook them. Same for the females...if I saw one at a distance I'd think Black Swallowtail or Pipevine.

According to my Kaufman guide they do stray northward onto the plains and through the Big Bend area to southeastern New Mexico.

There's also the Broad Banded, Thoas, Schaus's and a few others that are black and yellow with a bit of blue and red that can easily be confused with the GST. So everyone keep your eyes open and cameras ready!!!

~ Cat
~ Cat

Great work Cat!
Excellent idea to make this thread with the not so obvious differences. You're right about Thoas too..Some of the best leps find it hard to tell with these 3, especially when they are flitting around. They can get away from a good camera view so quickly too.

I agree, everyone keep the camera ready!

:-Deb

Yes, I was going to ask you what the differences were, but now I don't have to.
Thank you very much for the great explanations and pictures.
Josephine.

Once again I am thoroughly amazed! To even see the differences, much less commit them to memory..... Deb, you are a wonder!

Suzy

I'd like to see photos of Thoas and Schaus's if anyone has them.

By the way, this is the only photo of a Broad Banded Swallowtail I have. This one was nectaring on my duranta back in July 2006. It looked different so I ran back inside to get my camera...I was able to take only this one photo before it flew off never to return. Am hoping this year will bring more rarities because I'm ready for them.

~ Cat

That is really neat, you sure have a lot of variety.
Josephine.

Cat - I just can't get over the large variety of butterflies you get in your area! That's really amazing!!! Lucky YOU!!!!

Wow! TPP, thanks for the great lesson in ID-ing! Great photos, too.

Now someday I hope I get to see some in person! You are so lucky to have such variety! Butterfly heaven!

I like that Broad Banded Swallowtail . Hope you get to see and photograph them again. Beautiful butterflies. : )
~Lucy