Collected 5 Hemileuca caterpillars which are virtually identical to each other. Saw several more but left them where they were. The only plant I found them on was an oak tree, I believe live oak, but some were wandering nearby. I have them all in the same cage now with the oak leaves. I really think these are
H. maia or
H. grotei, but I wouldn't want to screw up a hemileuca ID
twice in one day :P.
... So I'll let some one else confirm it before I move it.