Cool, Ann! Yeah, the butterflies can actually stand freezing temps; the important thing is that they don't get their wings wet because ice crystals can form and that does kill them. It actually gets down to freezing temps even where the Monarchs spend the winter in Mexico. But the trees they hang on to do provide a micro climate that helps insulate them.
Speaking of Monarchs, Ken made and interesting point about the role of butterflies and moths in cultural traditions. Not all of them are as scary as his example! Monarchs tend to return to Mexico around the first of November when the Mexicans celebrate the Day of the Dead. They believe the Monarchs are the souls of the dead returning home. So if we lose the migration, it will be an environmental and cultural loss.
I thought you guys might want to see what those Hickory Horned Devils turn into. This is the mother of our caterpillars. Known as the Regal Moth, I got to collect the eggs she laid all over the screen in our flight cage. Moths are weird like that, sometimes. They don't actually have to lay eggs on a specific plant. People who raise moths will often take a female, tie a string around her and attach her to a tree. The males can smell her pheromones from miles away. Once fertilized, you can place some of these moths in a paper bag and they will lay eggs like crazy. I think that's mostly true for the family known as Saturniidae moths (basically, the big guys). Of course, you still have to feed the caterpillars the correct plant. You can see that the huge caterpillar turns into an equally big moth.
