of the Large Brown Hawk-moth (Psilogramma menephron, Sphingidae)
on African Tulip. I discovered it as I was getting the tree cut down - it is a noxious weed here; a previous owner must have planted it
I put some foliage with the caterpillar on it in a vase, but the caterpillar promptly disappeared - it was quite large so it may have wandered off to pupate.