Found dozens of these on my beans this morning. I don't recall ever seeing them before. A google search came up with green vegetable bug or green stink bug. According to google they were introduced into Australia in 1916 and have become a serious pest. Most of them were involved in the act of procreation and as I object to an orgy taking place in my garden I picked them off and trod on them. I guess there's worse ways to die than to die bonking.