Something you can't buy....vigilance. Fortunately they are stupid enough to be bright red. A good tip is to lay some white paper/cloth on the ground so that if it falls off it will be easy to spot as they always land on their black backs.

Last time I looked, there was no chemical control available to treat for these pests, though it has been suggested to me that Provado might, I'm not sure. Ask at the garden centre for treatments for lily beetle, make sure anything they point you at actually says lily beetle on it. If there is still no treatment, the only recourse is to pick the beetles off - this involves going out every morning and evening and any other time you're outside, stealthily creeping to the lilies, and just looking, very carefully - when you see one, grab it between forefinger and thumb and crush it (I usually have latex gloves on for this). The more beetles you kill, the less likely you are to have the revolting mess that occurs from the larvae being laid all over the plant, so that it looks like bird droppings - concentrate on killing the adult beetles.

Bamboo, do they like leeks as well as lilies? The reason why I ask is that I found The "bird droppings" like substance on my leeks last year.

Fortunately the lily beetle has not made it this far north, yet. We have a friend who is a major nursery man living in Harrow. When we stayed with him a few summers ago he introduced us to the beetle and encouraged us to join him in picking and squashing the beetles. If there was anything on the market to spray them with I am quite sure that it would have been available to him.

Try an AK-47 - the pesky little critters munched their way through ALL of my liles a couple of years ago - not a leaf/flower to enjoy by me, they ate the lot!

Heron - not sure about leeks but they go for fritillaries

I'm not sure about Leeks either Heron - according to my RHS book on pests, it's called Lily beetle because it affects lilies, doesn't mention anything else. Interesting though, I feel a question to the RHS coming on...