Willi wrote:
I found these nymphs two on different locations in autumn when I was
digging. Currently I'm keeping them in a glass vessel inside the house
in a cold spot, hoping that they will survive, and I will not miss the
right moment when the butterflies burst out of the shells with my
camera.

http://members.aon.at/supervague/images/garden.html

I wish you every success, I haven't tried doing something like that since I
was a kid. :-)