These sound like lily beetles. The best way of killing them is to creep up on them, and squash them. They jump off the lily if they feel any vibration, so you may want to spread an old sheet or something similar under the plants to catch them.

I think Beattie is right and they are lily beetles, I had them last year on a pot of lillies and they absolutly decimated them. I have found them again this year and as above I'm squashing them but also spraying with a general garden bug killer, I thinks its best to get them before they lay eggs as (in my experience) its the larvae that does the most damage and these are harder to see and they also cover their bodies in their own faeces as a camoflage!
Good Luck.

Flipping horrible things...ate one of my lilies to death last year i'm on the hunt this year and already found 3 on the same lily, blasted them with a spray called 'bug killer', keep your eye on them

Many thanks...ive collected around 10 at the moment and everytime i seem to find some their always copulating like ladybirds,and if you listen they make a little squeaking noise as well...bug killer it is then many more thanks.... ;-)

Sounds like you got to them just in time to prevent a REALLY BIG infestation, Windy!