Genus-level entry for the solitary, ground-nesting mining bees — one of the largest bee genera in North America, with several hundred species on the continent. They are among the earliest bees to emerge in spring, often flying while temperatures are still cold, which makes them key pollinators of early-blooming willows, maples, and fruit trees (apple, cherry, plum, pear) before most other bees are active. Females excavate underground nest tunnels in well-drained soil, frequently in dense aggregations, and provision each cell with pollen and nectar. Many Andrena are generalists, but the genus includes pollen specialists such as the spring beauty miner (Andrena erigeniae), which collects pollen only from Claytonia virginica.
Conservation
The genus as a whole is large and not assessed as imperiled, but most individual Andrena species lack formal conservation assessments, and narrow pollen specialists can be locally vulnerable where their host plants decline. No genus-wide IUCN or Xerces Society Red List status applies; do not read 'mining bees' as a single conservation unit.