Kendall County, TX
Saw this bee on one of the sunflowers in my in-law's backyard
Not a great photo, but definitely Sonoran. Deep bright yellow. Was flying over a patch of buckwheat but did not land on those flowers.
in upper center of photo.
See also http://www.inaturalist.org/observations/3542447
A lot of them travel through the circled area and also slightly north of that. Some kind of "super highway". One can stand in one spot and observe the back and forth. I was never able to find the target forage area or any nesting site. The area is mostly populated with invasive grass and russian thistle. Blooms included laurel sumac, bladder pod, acacia, ice plant, buckwheat, but bees never landed on them. First photo the bee is in the upper right corner, second, the bee is in lower left corner.