Dear Bugman –
Thanks for identifying my Sesiid moth – here’s another question. I apologize for the poor quality of the photo, but I barely had time to snap this pollen-laden bee before it burrowed into the sandy ground and disappeared. There was no sign of a tunnel or hole, it just dug in and vanished. This photo was taken in July at Pescadero Marsh, near the beach in California. Thanks so much for your great work!
We can’t give you an exact species because of the photo, but behavior leads us to believe this is a Digger Bee, genus Anthophora. These bees visit flowers and are often laden with pollen. Though solitary, they nest in colonies. According to the Audubon Guide: “Nest is contructed in clya or sand bank. Entrance is concealed by a downslanted chimney made of mud. The chimney and brood cells at ends of inner branching tunnels are thinly lined with mud. Each cell contains misture of honey and pollen plus 1 egg. Larvae feed, overwinter, and pupate in cell. Adults emerge in late spring.” So, there was a predug tunnel concealed by sand, allowing the bee to quickly disappear.