I have come across quite a few of these bright red and black-spotted cases on roses and other plants in the garden. Which is good new for my plants as they are the pupa casings for the Harlequin Ladybird (Harmonia axyridis).
You can see the details of the adult ladybird beginning to show as this is nearing completion of its transformation. I am quite amazed at how these still manage to move whilst in the metamorphoses state. They can flip themselves upright as can be seen in the image directly above, or lie flat as in the first image. Maybe it is to do with temperature regulation, or maybe they can sense potential threats.
Anyway, all those aphids better watch out!
Rear garden, Staffordshire, England. June 2017.