Clover Hayworm Moth vs Common Least Skipper

Hypsopygia costalis compared with Ancyloxypha numitor

Taxonomic Classification

Rank	Clover Hayworm Moth	Common Least Skipper
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	Hesperiidae
Genus	Hypsopygia	Ancyloxypha
Species	Hypsopygia costalis	Ancyloxypha numitor

Evolutionary Relationship

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

Conservation Status

Clover Hayworm Moth

LC — Least Concern

Common Least Skipper

LC — Least Concern

Physical Characteristics

Attribute	Clover Hayworm Moth	Common Least Skipper
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 Least Skipper

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Canada and 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 Least Skipper

The Common Least Skipper (<em>Ancyloxypha numitor</em>) is a small butterfly in the family Hesperiidae, classified as Least Concern on the IUCN Red List. It is native to Canada and the United States, where it typically inhabits virtually all terrestrial and freshwater habitats within its range, showing a particular affinity for moist, grassy areas near water. The species is among the smallest skippers in North America, characterized by orange and brown wing coloration and a rapid, low-flying flight pattern close to vegetation. Adults typically nectar on small flowers while larvae feed on grasses, particularly those in wet meadows, marshes, stream margins, and disturbed grassy areas. The Common Least Skipper is frequently observed in wetland margins, wet prairies, and roadsides with rank grass growth. Its wide distribution across North America and habitat generalism across moist grassland and wetland types support its stable population and Least Concern conservation status. Biological traits of this species remain poorly documented in the scientific literature.

Shared Countries

Both species can be found in 2 countries:

🇨🇦 Canada 🇺🇸 United States