Oh - and do you happen to know the wildflower ID?

but it looks like you have a couple dozen in Georgia, so you'll need someone a little more local to get you to species.

Thanks re the yellow-flowered plant - I'll check into it further.

I actually found these caterpillars here in North Florida on Ludwigia a few years ago, probably alternifolia (wet area?).

Yes - wet area. We were on a footbridge over a marshy area in the back of a large nearby lake. Last year I found an earlier instar on the same plant growing in a shallow cattail slough at a nearby wetlands. It was ID'd here and the photo is here ... that caterpillar was 2+ inches long and much more slender. I'm still amazed that they can get this big.

Thanks for the ID! I've seen Banded sphinx cat before and though it was big, it wasn't nearly this big. How often are they 6" long, and would this be the last instar? thanks again ...