Hello everyone!

I just moved to a new place temporarily and I've already started buying all kinds of seeds (and germinating some) to hopefully start a butterfly/wildlife garden next year. I don't have much right now to speak of, except for one thing- I found 7 (yes, seven!) beautiful 6th instar Tersa sphinx caterpillars the other day feeding on some poorjoe (Diodia teres), and they're all in the process of pupating. Now, I've raised lepidopterans before (mostly moths, but a couple of butterflies as well), but it's been a while. So I'm wondering- does anyone know how long tersa sphinxes take to eclose? I'm in NC's piedmont, and given that the particular host plants I've found them in have pretty much completely died, I'm guessing that they will overwinter as pupae? Or is there time for another generation?

If not, does anyone have tips on helping get them through the winter? These just made an extremely flimsy cocoon right at the surface of the ground with some leaves. The FAQ seems to say to just leave them outside and mist them occasionally, but I'm afraid their flimsy cocoon that literally consists of just one or two leaves on top of them will not protect them against the freezing cold, wind, and probable snow. Should I just pile a bunch more leaves on top of them and hope for the best?

Thanks!