Clover Hayworm Moth vs Coastal Flat-body

Hypsopygia costalis compared with Agonopterix yeatiana

Key Differences

Clover Hayworm Moth is Least Concern while Coastal Flat-body is Near Threatened.

Taxonomic Classification

Rank	Clover Hayworm Moth	Coastal Flat-body
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Arthropoda (Arthropods)	Arthropoda (Arthropods)
Class same	Insecta (Insects)	Insecta (Insects)
Order same	Lepidoptera (Butterflies & Moths)	Lepidoptera (Butterflies & Moths)
Family	Pyralidae	Depressariidae
Genus	Hypsopygia	Agonopterix
Species	Hypsopygia costalis	Agonopterix yeatiana

Evolutionary Relationship

Clover Hayworm Moth and Coastal Flat-body share a common ancestor at the Order level: Lepidoptera. (Butterflies & Moths)

View Order: Lepidoptera

Conservation Status

Clover Hayworm Moth

LC — Least Concern

Coastal Flat-body

NT — Near Threatened

Physical Characteristics

Attribute	Clover Hayworm Moth	Coastal Flat-body
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Clover Hayworm Moth

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

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

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.

Clover Hayworm Moth

The clover hayworm moth (Hypsopygia costalis) is a pyralid moth in the family Pyralidae, subfamily Hypsopygia, order Lepidoptera. The common name hayworm moth reflects the larval habit of feeding on dry plant material, including stored hay, dried plant debris, leaf litter, and decaying organic matter — a diet unusual among moths, most of which feed on living plant tissue. Larvae of H. costalis inhabit accumulated plant detritus such as thatch, stored grass clippings, compost, and dry stacks of hay or straw, earning the species its association with agricultural storage environments. Adults are small, brightly colored moths with distinctive red, yellow, and ochre wing markings that make them more visible than many pyralids, potentially functioning as aposematic coloration or mimicry. The species is distributed across Europe, including France, Germany, and the United Kingdom, extending to North America. It inhabits a variety of habitats wherever decaying plant material accumulates, including agricultural settings, gardens, woodland edges, and semi-natural grasslands. H. costalis is classified as Least Concern on the IUCN Red List, with populations considered stable and the species not subject to significant threats. The species has one generation per year in most of its range, with adults flying from late spring through summer. Larvae overwinter in plant debris. H. costalis rarely causes significant economic damage despite its association with stored plant material.

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.