Andreninae

Females of Ancylandrena, Andrena, and Megandrena possess broad, velvety facial foveae between the eyes and antennae—depressions absent or reduced to small grooves/pits at the upper eye margin in other Andrenidae. Unlike Panurginae, Andreninae lack yellow markings except potentially on the face, where such markings occur only in males. The subfamily can be distinguished from Colletidae (polyester bees) by mouthpart structure: Andreninae lack the bifurcated tongue and sinuous second recurrent wing vein characteristic of Colletes. Andreninae typically show heart-shaped faces in frontal view, compared to the round faces of mining bees in superficially similar groups.

Habitat preferences vary by genus. Andrena species occupy diverse environments including temperate forests, woodlands, agricultural areas, and urban gardens. Forest-associated Andrena species have been documented as obligate forest dwellers in eastern North American studies. Ancylandrena and Megandrena are restricted to desert regions of southwestern North America (Nevada, California, Arizona, Sonora, Baja California). Euherbstia and Orphana occur in desert regions of Chile. Many species nest in light, dry, sandy soils in sunny locations, including bare earth on south-facing slopes, footpaths, and short turf. Some utilize clay banks or exposed root plates of fallen trees.

Nearly cosmopolitan. Andrena has worldwide distribution. Ancylandrena and Megandrena: southwestern North America deserts. Euherbstia and Orphana: Chilean desert regions.

Spring-flying bees, with activity typically concentrated from March through May in temperate regions. Some species may extend activity into late summer. Univoltine life cycle with one generation per year is common, though some populations may show bivoltine patterns.

Solitary bees with no social colony structure. Each female constructs individual nests comprising tunnels with series of brood cells. Cells are provisioned with pollen and nectar, then sealed. Larvae develop within sealed cells, emerging as adults the following spring. Ground-nesting species excavate tunnels in soil; some may nest in aggregations with multiple individuals using favorable sites.

Solitary nesting behavior; females work independently without cooperative colony structure. Males typically emerge before females and may form mating aggregations, pursuing females aggressively. Some species nest in aggregations at favorable sites, creating dense concentrations of individual nests. Females carry pollen as loose dry powder on body hairs rather than mixing with nectar, facilitating pollen transfer between flowers.

Important spring pollinators of wildflowers and trees in forest and woodland ecosystems. Documented forest-associated species contribute significantly to pollination services in eastern North American temperate forests. Some species may pollinate economically important timber trees including maples, though this relationship requires further documentation. As generalist pollinators, they visit plants across multiple families.

Beneficial pollinators in agricultural and garden settings. Some species utilize bee hotels and artificial nesting substrates. Tawny Mining Bee (Andrena fulva) and Ashy Mining Bee (Andrena cineraria) are common garden visitors in Europe. Nest aggregations may cause concern to homeowners but are not aggressive. Educational value in demonstrating solitary bee biology and pollination services.

• PanurginaeDistinguished by yellow markings on body (absent in Andreninae except potentially on male faces); Andreninae females of three genera have broad facial foveae versus reduced foveae in Panurginae
• Colletinae (Colletes)Polyester bees have bifurcated tongue, sinuous second recurrent wing vein, and cellophane-like cell linings; Andreninae have simple tongue, straight second recurrent vein, and soil/plant material cell seals
• Halictinae (sweat bees)Often similar in size and general appearance; distinguished by wing venation details and lack of velvety facial foveae characteristic of many Andreninae

• BugGuide
• Wikipedia
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Brian's Bee Beard | Bug Squad
• Not-so Solitary Bees - Buglife Blog - Buglife
• A bumble bee, or not a bumble bee, that is the question: Miner bees, Anthophora abrupta — Bug of the Week
• Bug Eric: Polyester Bees
• Gardening for Solitary Bees - Buglife Blog - Buglife
• In a New Study, Spring Forest Bees Get Their Due
• The bee genusArhysosageBrèthes (Apidae: Andreninae: Calliopsini): new species, taxonomic notes and new distribution records from Brazil