Clover Hayworm Moth vs Common Flat-body

Hypsopygia costalis compared with Agonopterix heracliana

Taxonomic Classification

Rank	Clover Hayworm Moth	Common 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 heracliana

Evolutionary Relationship

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

Conservation Status

Clover Hayworm Moth

LC — Least Concern

Common Flat-body

LC — Least Concern

Physical Characteristics

Attribute	Clover Hayworm Moth	Common 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).

Common Flat-body

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

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.

Common Flat-body

<em>Agonopterix heracliana</em> is a moth belonging to the family Depressariidae within the order Lepidoptera. Commonly known as the common flat-body, this species is named for the flattened resting posture characteristic of the genus Agonopterix. The species is classified as Least Concern on the IUCN Red List, with no indication of significant population decline. <em>Agonopterix heracliana</em> is distributed across northwestern Europe, with documented occurrences in Belgium, Denmark, Norway, and Sweden. Larvae of this species are typically associated with plants in the family Apiaceae, particularly hogweed (Heracleum sphondylium) and related umbellifers, upon which they feed while sheltering in rolled or folded leaves. Adults are typically brownish with subtle markings and are active from late summer through winter and early spring, overwintering as adults — an unusual life history trait among moths. The species inhabits hedgerows, woodland margins, and meadows where its host plants are abundant. Biological traits of this species remain poorly documented in the scientific literature.

Shared Countries

Both species can be found in 4 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden