Awkward Clusterfly vs Coastal Silver-stiletto

Pollenia rudis compared with Acrosathe annulata

Taxonomic Classification

Rank	Awkward Clusterfly	Coastal Silver-stiletto
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Arthropoda (Arthropods)	Arthropoda (Arthropods)
Class same	Insecta (Insects)	Insecta (Insects)
Order same	Diptera (Diptera)	Diptera (Diptera)
Family	Polleniidae	Therevidae
Genus	Pollenia	Acrosathe
Species	Pollenia rudis	Acrosathe annulata

Evolutionary Relationship

Awkward Clusterfly and Coastal Silver-stiletto share a common ancestor at the Order level: Diptera. (Diptera)

Conservation Status

Awkward Clusterfly

LC — Least Concern

Coastal Silver-stiletto

LC — Least Concern

Physical Characteristics

Attribute	Awkward Clusterfly	Coastal Silver-stiletto
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Awkward Clusterfly

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Europe (5 countries) and North America (United States).

Coastal Silver-stiletto

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Awkward Clusterfly

The Awkward Clusterfly (Pollenia rudis) is a species in the genus Pollenia. It is currently classified as Least Concern on the IUCN Red List. Typically found in virtually all terrestrial and freshwater habitats.

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.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden