I was walking to work one morning and glanced at some weeds on the bank of a freeway bridge. I saw the most striking caterpillar that I'd ever seen in person. I could tell it would grow up to be a sphinx moth from its tail but thats all. It looked too exotic to be in the USA. I looked in Bug Guide and found that it was the spurge hawkmoth caterpillar (introduced into this country from europe). I took three of them home and three pupated a few days later. I'll post pupa photos soon