I was doing work today related to the master plan alignment of a pedestrian trail for the Poplar Run subdivision and Bel Pre Creek and Northwest Branch Park. As I was walking along a stream and meadow in Layhill, Montgomery County, Maryland, I heard the buzz of bees.
As I got closer to a fallen tree, the uprooted fan of the stumpage was alive with bee activity. The vertical wall of soil and roots was the home of a colony of digger bees (Anthophora), and most likely Anthophora abrupta. This bee is also known as the “chimney” bee.
This species look like bumble bees but a tad smaller. As I watched the bees fly around the root fan, I noticed that they were fast and nimble.
Digger bees are solitary, but will form a colony for the purpose of nest building. They are considered top-flight native pollinators and are harmless to humans. I was able to observe their operations up close and personal, while the bees worked around me.
If you look close at this photo you will see a digger bee flying into its nest hole opening (lower left). All you can see is the bee’s furry black rear-end and part of the buff-colored, furry mid-section.
Again, in this photo you can see a bee entering its nest hole opening. The fast-moving bee is out-of-focus. The entrance to the hole is concealed by a down-slanted chimney made of mud. The inside of chimney and brood cell tunnel are thinly lined with smooth mud. Each finished cell contains a mixture of honey, pollen, and one egg. The larvae will feed and pupate in the cell, emerging as an adult in late spring.
The following web-site is the best resource that I could find on the internet regarding digger bees and digger bee behavior. http://entnemdept.ufl.edu/creatures/misc/bees/anthophora_abrupta.htm