Update on the "Astounding!" caterpillar

Well, that was quick! I didn't even get around to posting my photos on BugGuide, but we have an ID for yesterday's caterpillar. A local naturalist left a comment on that post, with a link. Thanks!

What I have is a Cabbage White butterfly, Pieris rapae. The link answers a few of my questions:

1. It has settled in for the duration; they hibernate over the winter, hatching out in early spring.
2. The reason it wouldn't eat any of the veg. I gave it was that I gave it no brassicas, except for the hedge mustard I found it on. I should have tried cabbage out of my fridge.
   
3. I won't be able to tell if it is male or female until it hatches. Males have one spot on each wing, females have two.

And it brings up another question: why does Wikipedia say that hedge mustard, Sisymbrium officinale, is not a brassica, while another site says that it is? (A UK site says,

Cultivated brassicas are the primary foodplants including cabbages, and Nasturtium (Tropaeoleum majus). Wild crucifers such as Wild Cabbage (Brassica oleracea), Charlock (Sinapis arvensis), Hedge Mustard (Sisymbrium officinale), Garlic Mustard (Alliaria petiolata), Hoary Cress (Lepidium draba), and Wild Mignonette (Reseda lutea) are also used to a lesser degree.)

Hedge mustard as I found it.

And from a British site: same plant.