Beech Tarcrust vs Coastal Silver-stiletto

Biscogniauxia nummularia compared with Acrosathe annulata

Key Differences

Beech Tarcrust is Data Deficient while Coastal Silver-stiletto is Least Concern.

Taxonomic Classification

Rank	Beech Tarcrust	Coastal Silver-stiletto
Kingdom	Fungi (Fungi)	Animalia (Animals)
Phylum	Ascomycota (Sac Fungi)	Arthropoda (Arthropods)
Class	Sordariomycetes (Sordariomycetes)	Insecta (Insects)
Order	Xylariales (Xylariales)	Diptera (Diptera)
Family	Graphostromataceae	Therevidae
Genus	Biscogniauxia	Acrosathe
Species	Biscogniauxia nummularia	Acrosathe annulata

Conservation Status

Beech Tarcrust

DD — Data Deficient

Coastal Silver-stiletto

LC — Least Concern

Physical Characteristics

Attribute	Beech Tarcrust	Coastal Silver-stiletto
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Beech Tarcrust

Habitat

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

Range

Widely distributed across Asia (Taiwan), Europe (7 countries), and South America (Brazil).

Coastal Silver-stiletto

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Beech Tarcrust

The Beech Tarcrust (Biscogniauxia nummularia) is a species in the genus Biscogniauxia. Its conservation status is listed as Data Deficient, indicating insufficient data for assessment. Native to Asia and Europe and South 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.