I am in southern California and found a two inch long brown catterpillar nibbling voraciously on my ivy groundcover. I did not know that anything would eat tough old ivy but he loves it. He is hairless with some darker brown spots. I removed the sprout he was chewing on and put him on the glass top table on my patio and he is very happy there, chewing away. If he is some sort of wonderful butterfly, I will put him in my butterfly cage and let him pupate. But if he is a nasty, let me know!