Coastal Silver-stiletto vs Collared Parachute

Acrosathe annulata compared with Marasmius rotula

Taxonomic Classification

Rank	Coastal Silver-stiletto	Collared Parachute
Kingdom	Animalia (Animals)	Fungi (Fungi)
Phylum	Arthropoda (Arthropods)	Basidiomycota (Club Fungi)
Class	Insecta (Insects)	Agaricomycetes (Mushrooms)
Order	Diptera (Diptera)	Agaricales (Gilled Mushrooms)
Family	Therevidae	Marasmiaceae
Genus	Acrosathe	Marasmius
Species	Acrosathe annulata	Marasmius rotula

Conservation Status

Coastal Silver-stiletto

LC — Least Concern

Collared Parachute

LC — Least Concern

Physical Characteristics

Attribute	Coastal Silver-stiletto	Collared Parachute
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.

Collared Parachute

Habitat

Typically found in forest floors, decomposing wood, and soil ecosystems.

Range

Widely distributed across Europe (4 countries), North America (United States), and South America (Brazil).

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.

Collared Parachute

The Collared Parachute, known scientifically as <em>Marasmius rotula</em>, is a small saprotrophic fungus belonging to the family Marasmiaceae within the order Agaricales. <em>Marasmius rotula</em> is characterised by its distinctive wheel-like or parachute-shaped cap, which typically features radial gill-like ridges connected to a collar around the stipe rather than attaching directly to it — a feature that gives the species both its common and scientific names. This species typically grows on decomposing leaf litter, dead woody material, and forest floors in deciduous and mixed woodland. It is reported to occur in Belgium, Brazil, Denmark, Norway, and Sweden. As a decomposer, <em>Marasmius rotula</em> plays a role in nutrient cycling within forest ecosystems. Detailed biological traits including typical lifespan measures and physical dimensions are poorly documented for this species in available literature. The Collared Parachute is currently assessed as Least Concern on the IUCN Red List.

Shared Countries

Both species can be found in 4 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden