Patio Life: Unknown Caterpillar

I think this will be some type of sawfly, but I'm not sure about that.

I rescued some garlic mustard from the footpath and recenly found this guy and a smaller identical one on it. He hides during the day and feeds at night.
I cant see any real damage hes doing yet, but will keep my eyes on it, Sawflies can eat ALOT..lol and I've got at least one Orange Tip on this plant so need to keep it healthy, but there are only two