These green metallic bees were spotted on Douglas’ Threadleaf Ragwort (Senecio flaccidus var. douglasii) at the Claremont Colleges’ Robert J. Bernard Biological Field Station. I’ve previously seen green metallic bees at the field station only rarely, but they must love the Threadleaf Ragwort — quite a few of them have been on these flowers all this week, along with several other kinds of native bees. I think these must be Agapostemon. Is it possible to tell the species? Any information will be greatly appreciated!

If a photo of some other character would be useful, please let me know. I have more photos, and I can also go back and take even more.

Here is another photo taken at the same time, but it may be a different individual: