Pick them off and squash them

The red-backed lily beetle itself is a crafty little ****** as it will fall to the ground upside down displaying it's brown underside and therefore blend in with the earth; so very carefully place white kitchen roll round the base of the plant before lunging for the beetle - then you'll know you've got it! After which you can use the kitchen roll to wipe off and destroy the thoroughly nasty children of the beetle who eat the leaves while hiding themselves in their own excrement to escape the notice of birds. Good luck!

thanks nariz,now i know what that muck is on the leaves.love the idea with kitchen roll too.

You're welcome. :o))