Clavate Bent vs Cliff Mining Bee

Agrostis clavata compared with Andrena thoracica

Key Differences

Clavate Bent is Least Concern while Cliff Mining Bee is Extinct.

Taxonomic Classification

Rank	Clavate Bent	Cliff Mining Bee
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Magnoliophyta (Flowering Plants)	Arthropoda (Arthropods)
Class	Liliopsida (Monocots)	Insecta (Insects)
Order	Poales (Grasses)	Hymenoptera (Ants, Bees & Wasps)
Family	Poaceae (Grass Family)	Andrenidae
Genus	Agrostis	Andrena
Species	Agrostis clavata	Andrena thoracica

Conservation Status

Clavate Bent

LC — Least Concern

Cliff Mining Bee

EX — Extinct

Physical Characteristics

Attribute	Clavate Bent	Cliff Mining Bee
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Clavate Bent

Habitat

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

Range

Widely distributed across Asia (Taiwan), Europe (Finland, Norway, Sweden), and North America (Canada, United States).

Cliff Mining Bee

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Denmark, Luxembourg, Norway, and Sweden.

Clavate Bent

The Clavate Bent, Agrostis truncatula, is a small tufted grass in the family Poaceae found in rocky, open habitats across the western Mediterranean region, including Spain, Portugal, and northwestern Africa. The common name refers to the somewhat club-shaped or truncated appearance of its spikelets. Like other Agrostis species, Clavate Bent grows in dry, thin-soiled, often acidic substrates on cliff faces, rocky outcrops, and sandy soils at low to moderate elevations. It is a perennial species producing slender, erect culms with fine, narrow leaf blades and open to contracted panicles of small, one-flowered spikelets. The genus Agrostis is one of the most species-rich grass genera in temperate regions, with many species adapted to disturbed and marginal habitats where competition from larger grasses is reduced. Agrostis truncatula provides ground cover and forage in open habitats, contributing to soil stabilization on steep rocky slopes. The species is not currently considered threatened globally, though its preference for rocky, nutrient-poor habitats means that it may be sensitive to changes in land use and vegetation succession as shrub and forest cover expands in the absence of traditional grazing.

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.