They are also ladybirds, the top looks like a youngster and the bottom one an adult. Don't spray the plant, the young nymphs eat greenfly.

Ladybirds - Looks like they are just molting - shedding their baby clothes. They are beneficial bugs in the garden. Please let them live.

Thanks...I wouldn't touch them till I knew if they harmful or beneficial. I always thought Ladybirds were just red, I have found casings over the plant so guessed it was them shedding their skin. Thanks for the replies and so glad I don't have to remove them!