found this -Any advice on Lily Beetles Joey?
The only thing I've found that works is going out and checking the plants everyday and crushing the sods but I can't be arsed with that every single day. Instead I've just gave up on growing Lilies.
You can spray them with soapy water or water mixed with olive oil to kill them. Neem oil is a great way to kill the larvae and the bugs, be sure to spray the underside of the leaves. Spray again within 5 – 7 days to ensure there are no new eggs that hatched.
or I use this on most pest-using a dash of washing up liquid as a spreader per litre -