A large white

I grow nasturtiums, not for salads but for the variety of life that homes in on them.  They are full of holes, blackfly, next year's seeds, butterfly eggs and one, only one hoverfly case.  There are chrysalises on the windowsills which I fear have been predated but another single one residing in the dining room and which I hope will eventually pupate.  Isn't life wonderful?

My vertigo is gradually receding, thank you.  I'm such a lightweight.