Cliff Mining Bee vs Common Crocus

Andrena thoracica compared with Crocus vernus

Key Differences

Cliff Mining Bee is Extinct while Common Crocus is Not Evaluated.

Taxonomic Classification

Rank	Cliff Mining Bee	Common Crocus
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Magnoliophyta (Flowering Plants)
Class	Insecta (Insects)	Liliopsida (Monocots)
Order	Hymenoptera (Ants, Bees & Wasps)	Asparagales (Asparagales)
Family	Andrenidae	Iridaceae
Genus	Andrena	Crocus
Species	Andrena thoracica	Crocus vernus

Conservation Status

Cliff Mining Bee

EX — Extinct

Common Crocus

NE — Not Evaluated

Physical Characteristics

Attribute	Cliff Mining Bee	Common Crocus
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 Crocus

Habitat

Typically found in grasslands, wetlands, forests, and cultivated landscapes.

Range

Found across Europe (12 countries) and North America (Canada, United States).

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 Crocus

<em>Crocus vernus</em>, commonly known as the common crocus or spring crocus, is a small bulbous perennial plant in the family Iridaceae. Native to Europe, it has been widely cultivated and naturalized across North America. Common crocus typically grows in alpine meadows, subalpine grasslands, and woodland edges, often emerging through snow in early spring, making it one of the earliest flowering plants of the season. The flowers are solitary and cup-shaped, appearing before the leaves, and range in color from white and lilac to deep purple. The species has long been cultivated as an ornamental plant and is one of the parents of many garden crocus cultivars. Its corms are eaten by rodents and its flowers provide an early-season nectar source for bees and other pollinators. Biological traits of this species remain poorly documented in the scientific literature.