arrowroot vs Coastal Silver-stiletto

Thalia geniculata compared with Acrosathe annulata

Taxonomic Classification

Rank	arrowroot	Coastal Silver-stiletto
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Chordata (Chordates)	Arthropoda (Arthropods)
Class	Thaliacea (Thaliacea)	Insecta (Insects)
Order	Salpida (Salpida)	Diptera (Diptera)
Family	Salpidae	Therevidae
Genus	Thalia	Acrosathe
Species	Thalia geniculata	Acrosathe annulata

Evolutionary Relationship

arrowroot and Coastal Silver-stiletto share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

arrowroot

LC — Least Concern

Coastal Silver-stiletto

LC — Least Concern

Physical Characteristics

Attribute	arrowroot	Coastal Silver-stiletto
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

arrowroot

Habitat

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

Range

Widely distributed across Africa (Guinea), Asia (India, Taiwan), North America (Cuba), Oceania and the Pacific (Australia), and South America (Brazil, Colombia).

Coastal Silver-stiletto

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

arrowroot

The Arrowroot, Thalia geniculata, is a species. It is currently assessed as least concern on the IUCN Red List. Native to Africa and Asia 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.