What insect is digging in my soil in early spring? It could be the Andrenid Bee

Figure 1. A south facing slope at the Virginia Tech Golf Course is a favorite nesting spot for several burrowing insects throughout the year.  These mounds are made by the Andrenid bee (sometimes called the mining bee).

The hill leading up to old number 9 tee box at the Virginia Tech Golf Course is always teeming with burrowing insect activity on this dry, south facing slope.  According to VT Entomologist Eric Day, the mounding seen in Figure 1 is caused by the Andrenid bee (photo was taken in early April).  This is a native bee for which there are hundreds of species.  The Andrenid bee is a solitary bee (one female per tunnel/mound) but the females tend to congregate en masse, hence the literally hundreds of mounds on this hillside.  While the soil disruption is quite intensive at this time, this is one of the earliest, most important spring pollinators.  Unlike other very aggressive ground nesting species like yellow jackets (a form of wasp), the Andrenid bee is a very docile insect.  Their burrowing activity ceases in a few weeks so try to tolerate surface disruption if you can in order to take advantage of the pollinator capabilities of this beneficial insect.

Figure 2. There are over 1100 species of Andrenid bees. This photo shows a common Andrenid species in Virginia called Andrena dunningi.  © 2015 Cindy Pegg