Clover Hayworm Moth vs Common Fieldcap

Hypsopygia costalis compared with Agrocybe pediades

Taxonomic Classification

Rank	Clover Hayworm Moth	Common Fieldcap
Kingdom	Animalia (Animals)	Fungi (Fungi)
Phylum	Arthropoda (Arthropods)	Basidiomycota (Club Fungi)
Class	Insecta (Insects)	Agaricomycetes (Mushrooms)
Order	Lepidoptera (Butterflies & Moths)	Agaricales (Gilled Mushrooms)
Family	Pyralidae	Strophariaceae
Genus	Hypsopygia	Agrocybe
Species	Hypsopygia costalis	Agrocybe pediades

Conservation Status

Clover Hayworm Moth

LC — Least Concern

Common Fieldcap

LC — Least Concern

Physical Characteristics

Attribute	Clover Hayworm Moth	Common Fieldcap
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 Fieldcap

Habitat

Typically found in forest floors, decomposing wood, and soil ecosystems.

Range

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

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 Fieldcap

The Common Fieldcap (<em>Agrocybe pediades</em>) is a saprotrophic fungus belonging to the genus Agrocybe within the family Strophariaceae. It typically produces small, tan to pale brown cap-shaped fruiting bodies and is often found growing in clusters or scattered on lawns, grassy areas, forest floors, decomposing wood, and soil-rich ecosystems. The species typically inhabits forest floors, decomposing wood, and soil ecosystems, obtaining nutrients by breaking down dead organic matter. Its geographic range includes several European countries — Belgium, Denmark, Norway, Portugal, and Sweden — as well as the United States in North America. <em>Agrocybe pediades</em> is assessed as Least Concern on the IUCN Red List, reflecting its broad distribution and apparent stability. Biological traits of this species, including specific data on fruiting body size, lifespan, and ecological preferences, remain poorly documented in the scientific literature. Like other members of its genus, it typically fruits during warmer months and often appears after rainfall in nutrient-rich grassland and woodland habitats.