Cliff Mining Bee vs Dense Silky-bent

Andrena thoracica compared with Apera interrupta

Key Differences

Cliff Mining Bee is Extinct while Dense Silky-bent is Near Threatened.

Taxonomic Classification

Rank	Cliff Mining Bee	Dense Silky-bent
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Magnoliophyta (Flowering Plants)
Class	Insecta (Insects)	Liliopsida (Monocots)
Order	Hymenoptera (Ants, Bees & Wasps)	Poales (Grasses)
Family	Andrenidae	Poaceae (Grass Family)
Genus	Andrena	Apera
Species	Andrena thoracica	Apera interrupta

Conservation Status

Cliff Mining Bee

EX — Extinct

Dense Silky-bent

NT — Near Threatened

Physical Characteristics

Attribute	Cliff Mining Bee	Dense Silky-bent
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cliff Mining Bee

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Denmark, Luxembourg, Norway, and Sweden.

Dense Silky-bent

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, temperate grasslands and steppes, and flooded grasslands and savannas, among 4 distinct biome types within the Neotropic biogeographic realm.

Range

Widely distributed across Asia (Japan), Europe (9 countries), North America (Canada, United States), Oceania and the Pacific (Australia), and South America (Argentina, Chile). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

Cliff Mining Bee

The Cliff Mining Bee, Andrena species in the family Andrenidae, is a solitary ground-nesting bee that excavates tunnels in cliff faces, earthen banks, and compacted sandy or loamy soils, where the loose or friable substrates exposed in cliff profiles provide ideal nesting conditions. Mining bees in the genus Andrena are among the most species-rich solitary bee genera in the world, with hundreds of species across the Holarctic region, many narrowly specialized in their choice of pollen host plants. Female cliff mining bees construct vertical or angled burrows in cliff faces, with lateral cells off the main shaft, each containing a pollen ball and a single egg. Males are typically smaller and emerge before females to establish territories near nesting sites. Many Andrena species are oligolectic, collecting pollen from only a small number of plant species, making their populations sensitive to the availability of specific flowering plants in the landscape surrounding nesting areas. Cliff and bank nesting habitats provide well-drained, sun-warmed substrates essential for brood development. The loss of natural cliff faces and earthen banks to development, vegetation succession, and quarrying reduces available nesting habitat for cliff mining bees.