Coastal Flat-body vs Marsh Cress

Agonopterix yeatiana compared with Rorippa islandica

Key Differences

Coastal Flat-body is Near Threatened while Marsh Cress is Endangered.

Taxonomic Classification

Rank	Coastal Flat-body	Marsh Cress
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Magnoliophyta (Flowering Plants)
Class	Insecta (Insects)	Magnoliopsida (Dicots)
Order	Lepidoptera (Butterflies & Moths)	Brassicales (Brassicales)
Family	Depressariidae	Brassicaceae
Genus	Agonopterix	Rorippa
Species	Agonopterix yeatiana	Rorippa islandica

Conservation Status

Coastal Flat-body

NT — Near Threatened

Marsh Cress

EN — Endangered

Physical Characteristics

Attribute	Coastal Flat-body	Marsh Cress
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Coastal Flat-body

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, and Sweden. Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

Marsh Cress

Habitat

Found across multiple habitat types including boreal forests and taiga, flooded grasslands and savannas, and Mediterranean forests and woodlands, among 4 distinct biome types within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (Libya), Asia (India), Europe (Iceland, Norway, Sweden), and North America (Canada, Mexico, United States). Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Coastal Flat-body

Agonopterix yeatiana, the coastal flat-body, is a small moth in the family Depressariidae native to coastal and calcareous grassland habitats across western and northern Europe, with records from Belgium, Denmark, and Sweden. Moths in the family Depressariidae, commonly called flat-body moths due to the depressed posture they adopt when resting with wings held flat against the surface, are associated predominantly with umbellifer plants of the family Apiaceae as larval hosts. Agonopterix yeatiana larvae feed on wild carrot (Daucus carota), wild parsnip (Pastinaca sativa), and related coastal and grassland Apiaceae species, inhabiting the open, often calcareous or sandy habitats where these plants grow. Adult moths have greyish-brown forewing with a distinctive pattern of spots and dashes and reach approximately 8–12 millimeters in wingspan. The species is classified as Near Threatened by the IUCN, reflecting declines associated with the loss of traditional hay meadow management, coastal grassland degradation, and scrub encroachment that eliminates the open, flower-rich grassland habitats supporting its host plants. Agricultural intensification has reduced wild umbellifer populations significantly across lowland Europe, reducing food resources for larvae of specialist moths like A. yeatiana.