I came across a bunch of these larvae feeding on Coast Goldenbush (
Isocoma menziesii). They were near a lot of
Trirhabda flavolimbata larvae feeding on Coyote Brush (
Baccharis pilularis), and to my eye the larvae feeding on the two plants were indistinguishable. (See
this T. flavolimbata larva that I photographed a year ago in almost the same location, for example.)
I see from the
Trirhabda page that host plant is an important factor in determining species, that
Asteraceae (which includes
I. menziesii) are among its hosts, and that a (now dead, sadly) link had an image of an unidentified member of
Trirhabda, referring to it as common on
Isocoma venetus, which I gather is either a close relative of, or a synonym for the same species as,
I. menziesii.
Anyway, I'm curious if I'm correct in assuming this is a member of
Trirhabda, and if I could get some help figuring out what species it is. Thanks.