Erynnis pacuvius
(Lintner, 1878)
Pacuvius Duskywing, Dyar's Duskywing, Buckthorn Duskywing
Pronunciation
How to pronounce Erynnis pacuvius: //ɛˈrɪn.nɪs pəˈkuː.vi.əs//
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Identification
Identification to within the Erynnis requires examination of pattern details, particularly the arrangement of pale spots on the and , and often necessitates close or capture for reliable determination. E. pacuvius may be distinguished from other western Erynnis species by geographic range and period, though specific diagnostic characters are not provided in available sources.
Images
Appearance
Small to -sized with a wingspan of 29–33 mm. Duskywing skippers in the Erynnis typically have dark to blackish with small pale spots or ; specific markings for E. pacuvius are not detailed in available sources.
Habitat
Associated with supporting larval plants in the Ceanothus, which includes chaparral, woodland edges, and open slopes in western North America. Specific habitat preferences for are not documented.
Distribution
Western North America: southern British Columbia, Canada, and most of the western United States. Distribution records also indicate presence in Middle America, though specific localities are not detailed.
Seasonality
between June and July in northern portions of the range. Southern produce a second , extending the period later in the season.
Diet
feed on Ceanothus (Rhamnaceae). feeding habits are not documented.
Host Associations
- Ceanothus - larval Multiple in this are used as plants
Life Cycle
with , , , and stages. Larval development occurs on Ceanothus plants. Specific details on number of , stage, and sites are not documented.
Behavior
activity occurs during daylight hours. Specific behavioral observations such as perching habits, territoriality, or mating are not documented.
Ecological Role
function as on Ceanothus shrubs. may contribute to , though this has not been quantified. The serves as for various .
Human Relevance
No documented economic importance or direct human interactions. The is of interest to and naturalists in western North America.
Similar Taxa
- Erynnis tristisAnother western North duskywing with overlapping range; separation requires careful examination of patterns
- Erynnis propertiusWestern duskywing ; E. propertius has been recorded in early spring in California, potentially overlapping in range with E. pacuvius
More Details
Taxonomic Note
The was described by Lintner in 1878. Multiple reflect historical confusion or regional naming conventions: 'Pacuvius duskywing,' 'Dyar's duskywing,' and 'buckthorn duskywing' (the latter presumably referencing the Rhamnaceae, which includes Ceanothus and the true buckthorns in Rhamnus).


