Exciting

This is the first or second instar of the caterpillar of the Dainty Swallowtail Butterfly. 

It can chomp away at my lime tree to its little heart's content.  Never have they breed on my citrus before - at least I don't think so, they may have been on the lemon tree down the back, which looks like something has had a munch, but they are too high to see. Whereas this little chap is at eye level.