Brown Ear vs Coastal Silver-stiletto

Otidea cochleata compared with Acrosathe annulata

Key Differences

Brown Ear is Vulnerable while Coastal Silver-stiletto is Least Concern.

Taxonomic Classification

Rank	Brown Ear	Coastal Silver-stiletto
Kingdom	Fungi (Fungi)	Animalia (Animals)
Phylum	Ascomycota (Sac Fungi)	Arthropoda (Arthropods)
Class	Pezizomycetes (Pezizomycetes)	Insecta (Insects)
Order	Pezizales (Pezizales)	Diptera (Diptera)
Family	Otideaceae	Therevidae
Genus	Otidea	Acrosathe
Species	Otidea cochleata	Acrosathe annulata

Conservation Status

Brown Ear

VU — Vulnerable

Coastal Silver-stiletto

LC — Least Concern

Physical Characteristics

Attribute	Brown Ear	Coastal Silver-stiletto
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Brown Ear

Habitat

Native to Asia and Europe and North America, inhabiting ecosystems characteristic of the region.

Range

Widely distributed across Asia (Taiwan), Europe (4 countries), and North America (United States). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Coastal Silver-stiletto

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Brown Ear

The Brown Ear (Otidea cochleata) is a species in the genus Otidea. It is currently classified as Vulnerable on the IUCN Red List. Native to Asia and Europe and North America, inhabiting ecosystems characteristic of the region.

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.