Can you identify these bugs

My plum tree is covered in these bugs - can anyone identify them so I know if they are harmful or helpful. I think the top one black and orange may be a young ladybird. The other two seem to have a segmented front to the body but a group of legs/appendages at the  front. I cant find them on the internet as I don't know if they are beetles, bugs, insects or some other classification
Thanks for any help
Joan

Seems that way to me too.

Ladybird larva, ladybird pupa (the orange one) and... a ladybird 

I just released 100 British ladybird nymphs into my allotment, sorry they didn't look like that, they were skinnier and totally black.

Thanks for all your suggestions, I did not expect to see such a variety of the stages of a ladybird at one time on one tree. Bit of a quandry now, are they harmful harlequins  or good old british bugs? So long as they eat greenfly they are welcome in my garden.
Thanks
Joan

Is this also almost a ladybird?

Life cycle of the ladybird.