A few weeks ago, Z and I found a whole bunch of these caterpillars all over one of our fields.
We took two of them home, along with a handful of their host plants (asters, I believe) and set them up in our usual butterfly sprouting jar. I was skeptical that they would make it; they didn't seem to eat and grow with the voracity of monarch caterpillars, and the chrysalis of one fell off the side of the jar (also, they left behind a fuzzy bit of tail when they made their chrysalises, which I found mildly disturbling).
But, sure enough, a couple of weeks later, the first butterfly emerged.
Another week went by, and the second came out as well, fallen chrysalis and all.
It took me a while to find the time to look the species up, but I've finally puzzled out that our butterflies were Harris's checkerspots (Chlosyne harissii).
Now that I know we can successfully raise other butterflies, besides monarchs, I'm going to be on the lookout for more caterpillars (though not tomato hornworms--we tried those last year and they made our whole sun room stink like a feedlot). E already has a tent caterpillar in a yogurt container, which appears to have spun itself a bed of white candy floss, and has settled in for a good long sleep. I wonder what will come out the other end?