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Erynnis afranius Schrank, 1801
Afranius Duskywing; Duskywings
Family: Hesperiidae (Skippers)
Species account authors: Crispin Guppy and Jon Shepard.
Extracted from Butterflies of British Columbia.
Introduction to the Lepidoptera of BC
Introduction to the Butterflies of BC
The Families of Lepidoptera of BC

Photograph

© Norbert Kondla     (Photo ID #5005)

Map

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Distribution of Erynnis afranius in British Columbia.
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Source: Butterflies of British Columbia by Crispin Guppy and Jon Shepard © Royal BC Museum

Illustration

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Illustration Source: : Butterflies of British Columbia by Crispin Guppy and Jon Shepard © Royal BC Museum

Species Information


Adult

Adults of E. afranius and E. persius can sometimes be distinguished from E. pacuvius as noted earlier. Without examination of male genitalia, E. afranius and E. persius are impossible to differentiate in BC. Books on the USA fauna state that males of E. persius have long grey hairs on the dorsal surface of the forewings that are lacking on E. afranius, and that E. afranius has a wider light band on the outer side of the fringe that is visible with the naked eye. These characters are not reliable in BC. Females of E. afranius and E. persius are impossible to distinguish except by association with males. Males are distinguished by the shape of the valve. In E. afranius, the anterior lobe of the left valve is more pointed and the central lobe narrower than in E. persius. Two BC specimens with the genitalia of E. afranius have been identified. They have a wing pattern closer to that of E. pacuvius in that the forewing spots contrast strongly with the ground colour.

Immature Stages

Comstock and Dammers (1932) described the immature stages. The egg is white when laid, changing to cream or light yellow with 15 vertical ridges. The head of the mature larva is black with minute white points. The body is pale green with small white spots. The mid-dorsal line is dark and the lateral line is yellow. The pupa is vivid green, with a prominent black spiracle on the thorax.

Subspecies

None. The type locality of the species is Colorado.

Genus Description


The name Erynnis is derived from the Erinnyes or Furies who harried wrongdoers (Emmet 1991). Schrank used the generic name for all skippers, and used it to describe the erratic flight characteristic of skippers, as though they were avoiding the Furies. The Erinnyes sprang from the dark, thus the common name "duskywings" in reference to the dark wings. Scudder (1889b) was the first to use the name "duskywings" for the genus.

This and the remaining genera of the Pyrginae have rounded forewing tips, short discal cells, inconspicuous antennal tips, and porrect palpi. The genus Erynnis is distinguished by the mottled black background of the wings, hence the common name "duskywings". This Holarctic genus contains 17 Nearctic and 5 Palearctic species. Five species are found in BC. Closely related genera are all Neotropical. The larvae of this genus have been recorded as feeding on Quercus, Salix, Populus, Ceanothus, and Fabaceae. The various BC species cover this wide range of foodplant preferences, but individual species are restricted to one or a few closely related foodplants. Burns (1964) wrote the definitive work on the genus. Reference to Lindsey et al. (1931) is necessary for drawings of male genitalia, the only reliable structures for distinguishing most species. The shape of the left valve is the critical characteristic.

Biology


The eggs are laid on the tips of new growth of the foodplant. Elsewhere the species is reported to have two or three generations per year, but in BC it is univoltine. All of the afranius/persius complex specimens examined from BC indicate only one brood. The larvae have been recorded elsewhere from a variety of Fabaceae, including Lupinus (Lindsey 1927), Lotus (Comstock and Dammers 1932), and Medicago sativa (Emmel and Emmel 1973). Our populations must be reared to thoroughly understand their relationship to E. persius and other E. afranius populations.

Habitat


So far recorded in BC only from New Aiyansh, on the edge of a pasture.

Distribution

Distribution

The species occurs from AB to NM in the Rockies, and across AZ to southern CA. It has not yet been recorded elsewhere in the PNW, except ID, northeastern OR, and extreme southeastern WA.

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)		COSEWIC
NativeS1S3RedNot Listed



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