Coastal Silver-stiletto vs Common Crocus

Acrosathe annulata compared with Crocus vernus

Key Differences

Coastal Silver-stiletto is Least Concern while Common Crocus is Not Evaluated.

Taxonomic Classification

Rank	Coastal Silver-stiletto	Common Crocus
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Magnoliophyta (Flowering Plants)
Class	Insecta (Insects)	Liliopsida (Monocots)
Order	Diptera (Diptera)	Asparagales (Asparagales)
Family	Therevidae	Iridaceae
Genus	Acrosathe	Crocus
Species	Acrosathe annulata	Crocus vernus

Conservation Status

Coastal Silver-stiletto

LC — Least Concern

Common Crocus

NE — Not Evaluated

Physical Characteristics

Attribute	Coastal Silver-stiletto	Common Crocus
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Coastal Silver-stiletto

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, 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).

Coastal Silver-stiletto

Coastal silver stiletto (Acrosathe annulata) is a slender robber fly in the family Therevidae, native to northwestern Europe, including the United Kingdom, France, the Netherlands, Belgium, and Scandinavia. Adults are found on coastal sand dunes and sandy heathland, where they perch on bare sand to ambush small flying insects. Stiletto flies in the family Therevidae are characterised by a slender body, long pointed abdomen, and predatory habits; adults prey on a variety of small dipterans and other flying insects during warm, sunny periods. Larvae develop in sandy soil, where they are also predatory, feeding on other invertebrate larvae. Acrosathe annulata is a habitat specialist restricted to open, sandy coastal habitats with sparse vegetation—environments that have declined substantially across northwestern Europe due to dune stabilisation, recreational disturbance, and the cessation of traditional dune management. The IUCN lists it as Least Concern, though regional conservation bodies in the United Kingdom have flagged population declines. It is considered an indicator of high-quality coastal sand dune habitats and is monitored through national invertebrate surveys.

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.