Atrytone arogos

The Arogos Skipper closely resembles Atrytone delaware (Delaware Skipper), which occurs throughout the eastern United States. Accurate identification requires examination of wing border thickness and comparison of the paler yellow ventral wing surface. The species can be distinguished from other Atrytone species by its specific wing coloration and geographic occurrence in isolated prairie and grassland colonies.

Adults have vibrant yellow wings with dark blackish-brown borders. Males have thinner black borders than females. The underside of the wings is paler yellow than the upper surface. Wingspan measures 2.9–3.7 cm. Larvae are light bluish-green with a dark green dorsal line and a light tan head marked with orange and brown vertical lines.

Occupies grasslands, prairies, flat woods, and pine savannas. Requires dense stands of native grasses suitable for larval development. Host plant availability is a critical habitat component. Populations occur in isolated colonies, often several hundred kilometers from the Atlantic Ocean or Gulf of Mexico.

Occurs in isolated colonies in peninsular Florida, the Gulf Coast, southeast North Dakota, southern Texas, and the Colorado Front Range. Strays recorded from New Jersey to northern Arkansas. Possibly extirpated from New York, Minnesota, Wyoming, Illinois, North Carolina, South Carolina, Alabama, Iowa, Georgia, Montana, and Pennsylvania.

Larvae feed on leaves of Andropogon gerardi (big bluestem), Panicum species, Calamovilfa brevipilis, and other grasses. Adults feed on nectar from flowers including purple vetch, Canada thistle, dogbane, stiff coreopsis, purple coneflower, green milkweed, and ox-eye daisy.

• Andropogon gerardi - larval host plantbig bluestem
• Panicum - larval host plantgenus of grasses
• Calamovilfa brevipilis - larval host plant

Females deposit single cream-colored eggs with irregular red bands under leaves of host plants. Larvae pass through five instar stages, feeding on grass leaves. Fourth-instar larvae complete feeding in autumn and enter hibernation. Pupation occurs in a pale tan chrysalis formed about three feet above ground in vegetation. Adults emerge from chrysalis with physical appearance similar to the fifth instar larval form.

Males perch on low vegetation near host plants to locate females for mating. Perching sites are selected based on proximity to dense grass areas suitable for larval development.

Adults function as pollinators when feeding on nectar from diverse flowering plants. Larvae serve as primary consumers in grassland food webs. The species is an indicator of intact native prairie and grassland ecosystems.

The Arogos Skipper is listed as endangered, making it a subject of conservation concern and management planning. Habitat destruction through urban development, agricultural conversion, and fire suppression has contributed to its decline. Conservation efforts focus on preserving existing populations and conducting research to inform recovery strategies.

• Atrytone delawareShares physical resemblance and overlapping eastern United States range; distinguished by wing border characteristics and ventral coloration

The species was originally misidentified as Papilio vitellius, resulting in early research conducted under the wrong name. This has led to debate regarding its discovery date, with some sources incorrectly citing 1833–1834 rather than the correct 1837 date for the first subspecies description.

• endangered
• prairie specialist
• grassland dependent

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life