I've used insecticidal soap on similar bugs and it did work, it's not as hard a "shelled body" as a beetle. I don't know what else might be available where you are but there are insecticidal soap plus pyrethrin products that may work better. Safer makes one called Trounce. Going stronger than that, you would probably need to use a systemic insecticide if you wanted to go that route.
When you next see the bugs in a flower, invert a plastic sandwich baggie down over the top of the flower and see if you can catch some. You might need to break off the flower into the baggie as well. Then you can go to your local Extension office (or a knowledgeable garden centre if you don't have an Extension office), show them the bugs and ask what you could use to control them there in CA.