Coastal Silver-stiletto vs collared notchwort

Acrosathe annulata compared with Mesoptychia collaris

Taxonomic Classification

Rank	Coastal Silver-stiletto	collared notchwort
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Marchantiophyta (liverwort)
Class	Insecta (Insects)	Jungermanniopsida (Jungermanniopsida)
Order	Diptera (Diptera)	Jungermanniales (Jungermanniales)
Family	Therevidae	Jungermanniaceae
Genus	Acrosathe	Mesoptychia
Species	Acrosathe annulata	Mesoptychia collaris

Conservation Status

Coastal Silver-stiletto

LC — Least Concern

collared notchwort

LC — Least Concern

Physical Characteristics

Attribute	Coastal Silver-stiletto	collared notchwort
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 notchwort

Habitat

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

Range

Distributed across Norway, Sweden, and 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.

collared notchwort

The Collared Notchwort, known scientifically as <em>Mesoptychia collaris</em>, is a liverwort belonging to the family Jungermanniaceae within the class Jungermanniopsida. <em>Mesoptychia collaris</em> is a bryophyte — a non-vascular land plant — and represents one of the leafy liverworts, characterised by flattened, leaf-like structures arranged along creeping stems. This species is associated with moist, shaded habitats typical of temperate regions, including areas of Europe and North America. It is reported to occur in Norway, Sweden, and the United States. Like other liverworts, <em>Mesoptychia collaris</em> plays a role in moisture retention and habitat structure in the ecosystems it inhabits. Detailed biological traits including typical lifespan measures and physical dimensions are poorly documented for this species in available literature. The Collared Notchwort is currently assessed as Least Concern on the IUCN Red List.

Shared Countries

Both species can be found in 2 countries:

🇳🇴 Norway 🇸🇪 Sweden