This red and black beetle was spotted on California Buckwheat, Eriogonum fasciculatum, at the Claremont Colleges' Robert J. Bernard Biological Field Station. Today Hartmut Wisch happened to mention that he had recently come upon Cryptocephalus sanguinicollis sanguinicollis at the West Fork San Gabriel River (see this post), and that it might well live at BFS since Harsi Parker had found one in her pool, which is also in Claremont (see this post). And I realized I had just photographed a red and black beetle at the field station yesterday, and I think that is what it is. Any confirmation or correction will be greatly appreciated!