Common Least Skipper vs Sowerby's keeled slug

Ancyloxypha numitor compared with Tandonia sowerbyi

Key Differences

• Common Least Skipper is Least Concern while Sowerby's keeled slug is Data Deficient.

Taxonomic Classification

Rank	Common Least Skipper	Sowerby's keeled slug
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Arthropoda (artrópode)	Mollusca (Moluscos)
Class	Insecta (inseto)	Gastropoda (Gastrópodes)
Order	Lepidoptera (Butterflies & Moths)	Stylommatophora (Stylommatophora)
Family	Hesperiidae	Milacidae
Genus	Ancyloxypha	Tandonia
Species	Ancyloxypha numitor	Tandonia sowerbyi

Evolutionary Relationship

Common Least Skipper and Sowerby's keeled slug share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Common Least Skipper

LC — Least Concern

Sowerby's keeled slug

DD — Data Deficient

Physical Characteristics

Attribute	Common Least Skipper	Sowerby's keeled slug
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Least Skipper

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Canada and United States.

Sowerby's keeled slug

Habitat

Typically found in terrestrial and aquatic habitats including forests and freshwater.

Range

Found across Europe (10 countries) and Oceania and the Pacific (New Zealand).

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.