Syrphid Fly.

Basically every fly within the Family Syrphidae is called a Syrphid Fly. There are hundreds of the little buzzers. Most mimic a bee or wasp. Most pollinate flowers and are native in most of California.
You can tell them from bees because their antenna are short little stubby things instead of the longer antenna of the bees.Syrphid flies commonly have hood ornaments that the antenna is stuck on. Bee antenna come from right next to their eyes.
Bees and bumble bees tend to fly up to the flower and off of the flower, flies look like they're jumping off when they take off. watch them for a while and you'll notice they are a little different, the difference is enough that you can spot which is which without being that close.