id please of bug quite urgent

hi sorry there is no photo of this as my camera is broken but I hope that someone might be able to id this on description only.

it is about 1/2in long, the body tapers down to the back end, it has a black head area and the rest of the back area is red not sure if it flys or not as it was sat still when I found it.
I found it in one of the makeshift greenhouses (food bags) that I took of my runner beans seedlings which are in toilet rolls sown in seed compost.
the makeshift greenhouse was by other potted houseplants so again not sure if it had transfered from one of them though again they are in multipurpose compost.

 

This sounds like the lily beetle but strange because it will only eat lilies. The only other red beetle I know is the soldier beetle which eats a wide variety of plants, but it has a red head and feelers. :confused: