University of Maryland Extension

Mining Bees - Lawns

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closeup of mining bee
Mining bee (Andrenidae)
Photo: Cheryl Moorehead, Bugwood.org

Key points

  • Mining, ground, or digger bees nest in burrows in the ground.
  • Mining bees are solitary bees. Each mining bee female usually digs her own burrow to rear her young.
  • Large numbers of these bees may nest close together if soil conditions are suitable and will fly just above the ground. When this happens they frequently become a nuisance to some people.
  • They are not aggressive, seldom sting, and their flying activity lasts only 2 to 4 weeks.
  • Sometimes large numbers of males will fly about the same spot for several days in a mating display.
  • Bee populations can fluctuate dramatically from one season to the next.

General Information

  • Mining bees range in size from about the size of honey bees (largest), down to much smaller species.

  • The larger bees are furry and usually darker in color than honey bees. Some are brightly striped, while others are shiny metallic green.

  • Mining bee burrows tend to be located wherever there is exposed soil, thin grass, and good drainage. The holes are about 1/4 inch in diameter and are sometimes surrounded by a small mound of soil.

  • Burrow structure varies according to species but often there is a vertical tunnel with smaller side tunnels that terminate in a single cell.

  • The female mining bee stocks each cell with pollen and nectar she collects from flowers and then deposits an egg on the food mass.

  • As eggs hatch and larvae develop they consume the stored pollen and nectar.  When mature, each larva becomes a pupa (resting stage) and then becomes an adult bee.

  • The adult bees overwinter below ground in the burrow site. During the next spring or early summer, the adults emerge, mate, and the females begin burrow excavation. 

Management

  • Mining bees are important pollinators and control should be avoided if possible.

  • Heavy watering with a lawn sprinkler will discourage nesting behavior.

  • Long-term control involves the elimination of bare-ground areas and the establishment of dense turf to discourage these bees.

  • If the area is not conducive to a healthy lawn, groundcovers or heavy mulches may provide an alternative solution. 

Additional Resource

Rev. 2020

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