I have no idea - and my Kaufman field guide offers no assistance with that. BUT... all that aside... He/She is BEAUTIFUL!

~Laura

Thanks, Laura!
I meant to say if the third SPOT, not bar - which is a long one - is filled in, it's a male. At least I think that's how you tell males and females apart.
Sherry

I thought you were the one that taught us to tell by that line (or lack of line) on the chrysalis.

I consider you the GST expert here so if you don't know, I sure as heck don't.

'Wasn't me, KC - hey, that rhymes!

Giant swallowtails' chrysalides don't even change in appearance/become translucent right before they emerge, at least I've never seen any difference. I just check the cages in the morning and, bingo!, there's a big butterfly.

Sherry

My bad. Luckily I had it bookmarked. It was one of other experts who does not show up as much these days.

Gender ID via pupa is about half-way down the page.

Here is a link that might be useful: Giant Swallowtail Guide

That's an interesting way to determine the sex of giant swallowtails! I don't know how I missed that thread, since I'm here nearly all the time. All my GST chrysalides have pupated on the frame or the mesh of the cages, and the pertinent area is hidden, except one that pupated on the underside of the paper towel. I clipped the sling so I could put the chrysalis in a position where I could see what was there - this must be a female -
{{gwi:507948}}
Giant swallowtail chrysalides are interesting - they look like a rough, lichen covered log with a zipper on the back! :)
I put this chrysalis in a cage that only has three black swallowtail chrysalides, so when it emerges, I'll know for sure it's the right one. I'll take a picture of her and see if she has the female characteristics my book shows for females.
I released another GST today. Its big spot was filled in and all its spots were big, like the others, so I'm assuming he's a male, too. Several GSTs have been flying in my garden today - what a great sight! Giant swallowtails seem to stick around more than many other butterflies after I release them.
Sherry

I have always thought that the females were much larger. Generally that is what I have noticed when they are laying eggs.

Miss Sherry,

Found the thread where the other Sherry posted about her way to determine sex via pupae. Somebody I know has some great GST pics in that thread. :D

KC

Here is a link that might be useful: Gender ID on GST butterflies?

Thanks, KC!
I released two more today, and I think one is a male and one is a female. Both were very big!
There was a GST caterpillar that pupated very early and made a small chrysalis - the discarded skin didn't come off, so it was a pitiful looking thing. I didn't try to get it off, because it looked stuck on, and I was afraid I would cause it to ooze by forcing the old skin off. It emerged the other day, a perfect little giant swallowtail, no bigger than a black swallowtail! I didn't get a picture, but you wouldn't have been able to tell how little it was anyway.
The reason I continue to question the sex of GSTs is that last year sometime I saw a GST with a thick bar laying eggs - this makes me think that bar size isn't everything. I've also seen some thick-barred individuals whose third from the end spot wasn't completely filled out. It's confusing!
I took a picture of the one that I THINK is a female -
{{gwi:507949}}
Sherry

Funny I spent way too much time trying to figure this one out a while back. I think I decided that the one with the black spot in the 3rd yellow mark was the female. But can never see the back of the pupa w/out moving it, which I don't want to do. (except for when I have to, like when it pupates on my husband's shoe.)

Here is a link that might be useful: male or female GST

I think you're right, if THEY know which sex they are, that's all that counts! :)
Sherry

The temperature got real hot, then we had a brief, heavy shower, so the outdoors is like a sauna - a sauna that fogged up my camera lens. Still, when I went outside and saw this couple, I remembered this thread and had to take their foggy picture. They were hiding in the woods -
{{gwi:507950}}
They probably didn't need to check out each other's yellow bars! :)
Sherry