|scientific name Erynnis afranius |
common name Afranius Duskywing
Valley sides and coulees of the short-grass prairies.
Two broods annually, with emergence peaks in late May and again in late July.
The duskywing skippers (genus Erynnis) can be a challenge to identify, particularly in prairie habitat where all three species may occur together. The white spots in the forewing tip are useful characters for separating these species: Afranius and persius both have at least two (usually three or four) spots, while the Dreamy Duskywing (Erynnis icelus) has only one spot or none at all. Afranius is more difficult to separate from Persius; Afranius is more brown in colour, not grey, and the fore- and hindwing do not contrast grey (forewing) and grey-brown (hindwing) to the same extent that Persius does; Individuals from short-grass prairie habitat in August are almost certainly E. afranius, since E. persius does not have a second brood. Uncertain specimens must be dissected for diagnostic characteristics of the male genitalia; see Scott (1986) and Guppy & Shepard (2001) for illustrations.
The egg is cream-coloured when first laid, eventually turning reddish orange (Bird et al. 1995). First instar larvae are yellowish brown with a light brown head (McCabe & Post 1977). The pale green larvae have a dorsal dark stripe and a black head when mature, and overwinter. Pupae are green (Bird et al. 1995).
No obvious concerns.
Females lay eggs on Buffalo Bean (Astragalus crassicarpus) in Alberta (Bird et al. 1995), and other legumes serve as larval foodplants elsewhere in Canada (Layberry et al. 1998).
Essentially a species of the Great Plains, ranging from the southern Prairie Provinces south to Mexico (Opler 1999). There are disjunct populations in the Yukon and Alaska and west-central BC whose taxonomic status is unresolved, but are currently treated as E. afranius (Guppy & Shepard 2001).
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