Montana Field Guide

[From Ferris and Brown 1981; Scott 1986; Opler and Wright 1999; Glassberg 2001; Pyle 2002] Forewing 3.5-4.0 cm. Tails mostly short across much of range, longer in the south. Abdomen completely black or with short pale yellow line on last half. Uppersurface usually black with narrow pale marginal and postmedian yellow spot bands on both wings, hindwing with series of submarginal iridescent blue patches (more extensive on female), hindwing orange eyespot with centered black pupil. Undersurface similar to uppersurface.

One flight; mostly May to June in the north, March to May in the south, a partial or full second flight July to August in Colorado Arizona, and Nevada (Scott 1986). March to July, earlier in south and Pacific lowlands, later in north and mountains (Glassberg 2001). Mid-May to mid-July in Colorado (Scott and Epstein 1987), late June to mid-July at high elevation in northern California (Shapiro 1977), late March to mid-August in Washington and Oregon (Pyle 2002), late March to late July in Oregon (Warren 2005), June and July in British Columbia (Guppy and Shepard 2001).

Best determined by mostly black abdomen with short pale yellow stripe on posterior half, black uppersurface and undersurface with narrow pale marginal and postmedian yellow spot bands on both wings, hindwing with series of submarginal iridescent blue patches, hindwing orange eyespot with centered black pupil.

Non-migratory.

Rocky terrain, dry mountainous areas, dry conifer woodlands, hilltops, rocky slopes, canyons, above treeline in rocky alpine terrain (Eff 1962; Shapiro 1977; Ferris and Brown 1981; Scott 1986; Opler and Wright 1999; Glassberg 2001; Pyle 2002; Warren 2005). Habitat in Montana not described but probably similar.

Larval food plants are members of the Apiaceae, and include Aletes, Cymopterus (multiple species), Harbouria, Lomatium (many species), Pteryxia (multiple species), and Tauschia (multiple species) (Emmel and Emmel 1963, 1964, 1967, 1968, 1974; Newcomer 1964; Shapiro 1977; Scott 1986, 1992, 2006; James and Nunnallee 2011). Adults feed on flower nectar (including Apocynum, Amelanchier, Brodiacea, Carduus, Cirsium, Convulvulus, Cryptantha, Delphinium, Erysimum, Grindelia, Hackelia, Helianthus, Jamesia, Lesquerella, Lomatium, Mentha, Ribes, Scutellaria, Senecio, Symphyotrichum) and mud (Eff 1962; Emmel and Emmel 1967, 1974; Pyle 2002; James and Nunnallee 2011; Scott 2014).

Females lay eggs singly (30 eggs total over six days reported for one female) on the undersides of host plant leaves and outsides of bracts, usually while fluttering wings (Emmel and Emmel 1964; Scott 1986; James and Nunnallee 2011). Eggs hatch in about 6-7 days (depending on temperature), develop to L5 instar and pupae in about 18-30 days (depending on temperature), with most development time (about 50%) spent as L5 instar; pupae over summer and overwinter, spending about 11 months to two years or more as pupae (Newcomer 1964; Scott 1979, 1986; Guppy and Shepard 2001; James and Nunnallee 2011). Larvae feed mostly during day but also at night on host plant leaf margins when young, whole leaves when older; rest at base of host plant, build no nest (Scott 1986). Males perch and patrol throughout the day, frequenting hilltops, rocky slopes, canyons, roadsides, along rivers, while seeking females (Scott 1975b, 1986; James and Nunnallee 2011).