So I noticed that some of the foraging bees have this white powder looking substance on their thorax. See pics. I live in a town called Castro Valley, CA and it’s February. It’s unusually mild for this time of year and the bees are in full swing. I’m hesitant to do a hive inspection as I prefer to let them bee (pun). I’ve read that this can be associated with white pollen rubbing off on the bees from particular flowers.
Looks fine to me. Could be pollen, or could just be chitin (bee fuzz). If there are a lot of young foragers (likely at this time of year in your climate), they will still have hairy thoraces. This wears off as they age, because they can’t regrow it. I wouldn’t worry.
My bees in San Diego love rosemary too. Nice that yours has so many flowers! Rosemary pollen is cream to white, just FYI.
