It's that time of year for the green sweat bees Agapostemon Guerin-Meneville to return to the garden. These are the A. texanus species, which are the most common in California gardens.
I've noticed in the past, and now again, that these bees often visit cosmos blossoms.
This male green metallic sweat bee spent a long time on the blossoms of the Orange Sulphur Klondike Cosmos plant.
The males of this species have green heads and thoraces, and yellow-and-dark striped abdomens, with yellow markings on their legs and face.
I don't know if it was the same green sweat bee that visited the patio, earlier in the afternoon, but there was another male visitor on our Rudbeckia hirta‘Chim Chiminee’ plant.
Both the cosmos and rudbeckia (Black Eyed Susan) blossoms provide pollen and nectar.