Bembix, Sand Wasp
This Bembix was on a California Buckwheat, Eriogonum fasciculatum.
They can be pollinators or predators of flies, and occasionally other
small instects. This one was hunting for flies. Jumping from flower
to flower looking for prey. This wasp is about an inch (2-3 cm) long
and focused on finding a fly to bring back to the nest.