For the past few springs, my lilies have been infested early in spring by red lily leaf beetles, which, if left alone, will destroy lilies and related plants. I have resorted to hand picking of beetles off my plants combined with a good spray of insecticide just once early in the season, at a time when there are no other beneficial insects (such as bees) in the garden. I am pleased to say that once again, my lilies have survived while the beetles have not.