Cliff Mining Bee vs Common Milkwort

Andrena thoracica compared with Polygala vulgaris

Key Differences

• Cliff Mining Bee is Extinct while Common Milkwort is Vulnerable.

Taxonomic Classification

Rank	Cliff Mining Bee	Common Milkwort
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Magnoliophyta (Flowering Plants)
Class	Insecta (Insects)	Magnoliopsida (Dicots)
Order	Hymenoptera (Ants, Bees & Wasps)	Fabales (Legumes & Allies)
Family	Andrenidae	Polygalaceae
Genus	Andrena	Polygala
Species	Andrena thoracica	Polygala vulgaris

Conservation Status

Cliff Mining Bee

EX — Extinct

Common Milkwort

VU — Vulnerable

Physical Characteristics

Attribute	Cliff Mining Bee	Common Milkwort
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.

Common Milkwort

Habitat

Typically found in diverse terrestrial habitats from tropical forests to temperate regions.

Range

Widely distributed across Europe (6 countries), North America (Canada, United States), and Oceania and the Pacific (Australia). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

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.

Common Milkwort

Common Milkwort (<em>Polygala vulgaris</em>) is a small flowering plant in the genus <em>Polygala</em>, family Polygalaceae. It is distributed across Europe, North America, and Oceania, with confirmed presence in countries including Australia, Belgium, Canada, Denmark, and Finland. Typically found in diverse terrestrial habitats ranging from tropical forests to temperate grasslands, this species favors calcareous grasslands, heathlands, and other open, well-drained habitats. Common Milkwort produces small flowers in shades of blue, pink, or white, and is associated with traditional grassland communities. Currently classified as Vulnerable on the IUCN Red List, the species faces significant conservation challenges across its range, likely driven by habitat loss through agricultural intensification and the decline of traditionally managed grasslands. Specific biological measurements such as lifespan, length, and weight are not documented in available records. The genus name <em>Polygala</em> derives from Greek meaning "much milk," reflecting a historical belief that the plant could increase milk production in livestock.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden