Black spiny caterpillar - Vanessa atalanta
Agoura Hills, Los Angeles County, California, USA
October 10, 2004
Discovered while weeding out Baby Tears from flower garden. I'm not sure if it was living there or just passing through. It was beneath a Buddleia and may have fallen from it.
Vanessa atalanta is known to use Baby Tears as a host plant in the abscence of nettles. That's my best guess.