Ground-nesting bees: Meet the miner bee

By Matt S., County Extension Director and Horticulture Agent, Pitt County
Though I normally write about plants, there are many insects we encounter while outside gardening. Some can be problematic for our plants, but most are non-pests and many are beneficial. Everyone knows about honey bees, but less well understood are ground-nesting bees such as miner bees. Miner bees are active for a few weeks in early spring and are out and about now.

Miner bees (Genus Andrena, Family Andrenidae) live in the ground, particularly in areas with dense soil and sparse vegetation.  Unlike honey bees, they do not all nest together in a single hive, but rather each bee will create its own individual tunnel in the ground. Thus, a yard that has miner bees may have hundreds of small holes in the soil in relatively close proximity. When the bees hover above

Miner bees (Anthophora abrupta) are important pollinators.

their nests in the day, the sight of so many bees flying around in the yard at ankle or knee height can be a bit intimidating. 

An Andrena miner bee pokes its head out of a tunnel it made in an urban yard.

Miner bees, however, are not aggressive. They very rarely sting. The ones that you see flying are generally males, and do not have stingers. The females can sting, but they dig the holes in the ground and raise the young, so they rarely leave the ground. You can walk through a group or even mow over them without fear of being stung, though on rare occasions if a female becomes trapped inside your clothing, she may eventually sting you.

As honey-bee populations decline, the importance of miner bees and other native bee species is increasing, because, though they do not produce honey, they are important pollinators. Miner bees are known to frequent many ornamental and edible flowering plants. Other solitary ground-nesting bees, such as mason bees (Genus Osimia, Family Megachilidae), and digger bees (Genus Anthophorini Subfamily Apinae of the family Apidae), also play an important role as pollinators and lack aggressive characteristics.

Because of their role as pollinators and their lack of aggression, we do not generally recommend any chemical treatment or control measures for miner bees and other solitary nesting types, despite the fact that they can be a slight nuisance for a few weeks each spring if nesting in an undesirable location. If you simply can’t stand them, they do not like to nest in wet soils, so

Andrena miner bees make numerous holes in the ground

heavily watering the area may drive them to nest somewhere else without killing them. Once you’ve successfully relocated them, reseeding the area with grass may prevent them from returning next year.

Yellowjackets pollinate flowers but are aggressive.

Of course, there are other types of flying insects that nest in the ground and are aggressive. The most common of these are yellowjackets (Genus Dolichovespula or Vespula, Family Vespidae), which are actually wasps. Yellowjackets do have some value as pollinators, but they are aggressive and nest in groups. If you should step on, mow over, or otherwise encounter a yellowjacket nest in the ground, you might be in for some trouble. If you find one of these nests,

the best way to treat it is to spray into the nest in late afternoon or early evening with a hornet and wasp spray. Most of the colony will be inside the nest at this time of day, so a good strong spray will likely eliminate them.


Matthew Stevens is the County Extension Director and Horticulture Agent for North Carolina Cooperative Extension’s Pitt County Center.  If you have questions about this article or gardening in general, please contact the Pitt County Extension Master Gardener Infoline at 252-902-1705. 

Photo 1:  Miner bees are important pollinators.
Photo by Charles Schurch Lewallen, U.S. Forest Service

Photo 2: An Andrena miner bee pokes its head out of a tunnel it made in an urban yard. Photo by Matt Bertone, NC State

Photo 3: Andrena miner bees make numerous holes in the ground
Photo by Matt Bertone, NC State

Photo 4: Yellowjackets pollinate flowers but are aggressive.
Photo by IStock  credit Apodiam