Quote Originally Posted by Mendip View Post
This was only an empty shell, and I'm wondering if the preying mantis have a pupae stage and this was what's left after hatching.
No they don't, the nymphs are the same as the adult but smaller. They go through stages of development where they shed their exoskeletons as they grow larger. The wings come with the final adut stage.

Praying Mantis Life Cycle – Facts, Diagram, Stages, Video - Praying Mantis