Insect dilemma!

OK, it's really nice that you've met each other...but I don't want you breeding! I'm always thrilled when lots of different insects start appearing in the garden, but a few aren't so welcome. These are Lilly Beetles, Lilioceris lilii, and they are a serious pest. Both adults and larvae chew through lily leaves and flower buds. The larvae are disgusting enough to cover themselves in their own excrement for camouflage. Last year I wasn't tough on them - I may have to be this year if my visiting garden birds don't help me out.