I have a lot of lilies in pots and last year I decided I would not grow them again if they were damaged as much this year by the lily beetle. When I saw the first pair (always in pairs on top of one another..ahem) I killed them and then sprayed all of them with a general purpose insect spray I bought from Focus in their sale when they were taken over. Not seen any since. I thought I was going to have to buy expensive Provado!