Montana Field Guide

[From Ferris and Brown 1981; Scott 1986; Layberry et al. 1998; Opler and Wright 1999; Glassberg 2001; Pyle 2002] Forewing 1.4-1.5 cm. Forewing of male with narrow stigma and black interior felt, female with dark patch in forewing cell. Uppersurface tawny-orange with dark border and basal area, forewing with white spots in the apical and submarginal areas (more extensive in females); undersurface of hindwing with white spots of postmedian band connected and forming chevron, veins usually white or silvery, submarginal patches blotchy dark brown.

One flight, mid-June through July at high elevation and in California and Oregon; two flights, mainly June to August in the prairies; severel flights, late April to mid-September southward (Scott 1986). One-brood areas, mainly June thorugh July; two-brood areas, May to September (Glassberg 2001). Mid-June to late July in Canada (Layberry et al. 1998). May to September in the Rocky Mountain states (Ferris and Brown 1981). Late May to late August in Colorado (Scott and Scott 1978), early June to late September in North Dakota (McCabe and Post 1976), Mid-May to late June in Oregon (Pyle 2002; Warren 2005).

Best determined by a combination of the hindwing undersurface with white spots of postmedian band connected and forming chevron, veins usually white or silvery, submarginal patches blotchy dark brown.

Non-migratory.

Short-grass prairie, grassy alkali flats, open woodland, sagebrush, above treeline in alpine terrain (Ferris and Brown 1981; Scott 1986; Bailowitz 1988; Layberry et al. 1998; Opler and Wright 1999; Glassberg 2001; Pyle 2002; Warren 2005). Also present in prairie riparian communities dominated by grasses and open woodlands, avoiding dense Tamarix stands (Nelson and Wydoski 2008). Habitat in Montana not described, but probably similar; county records include reports from prairie grassland and pothole regions, and alpine terrain in mountains (FLMNH Lepidopteristis' Society database).

Larval food plants are grasses, including Achnatherum, Bouteloua (multiple species), Erioneuron, and Stipa; also Poa in captivity (Ferris and Brown 1981; Scott 1986, 1992; Layberry et al. 1998; Warren 2005). Adults feed on flower nectar (including Agoseris, Arabis, Asclepias, Astragalus, Carduus, Chrysothamnus, Cirsium, Cryptantha, Erigeron, Erysimum, Grindelia, Helianthus, Heterotheca, Hymenopappus, Liatris, Lupinus, Medicago, Monarda, Opuntia, Oxytropis, Penstemon, Potentilla, Senecio, Symphyotrichum, Tamarix, Taraxacum, Thelesperma, Verbesina) and mud (Scott 2014).

Limited information. Females lay eggs singly on or near the host plant (Scott 1986, 1992). In captivity, develop from oviposition to pupae in 83-114 days, adults eclose (emerge) from pupae in captivity in 19-36 days (Scott 1975e). Larvae feed on host plant leaves, construct silk-tied leaf nests, the overwintering stage apparently unreported (Scott 1986). Males perch throughout the day on small prairie elevations, hilltops, and desert bajadas while awaiting passing females, which they pursue (Scott 1975b, 1982, 1986; Warren 2005).