Caterpillars on the move, continued

This handsome caterpillar and its colleagues are having a real party on our alamanda plants (Alamanda cathartica) at the Bosque. I never saw them feeding on these particular vines before and I certainly don't remember this character. I wish I had paid attention to what it was doing instead of trying to get a picture. Could it be that it was chewing on that stem? I think so.