Montana Field Guide

[From Ferris and Brown 1981; Scott 1986; Opler and Wright 1999; Glassberg 2001] Forewing 3.8-4.5 cm. Tailed, thorax shoulders usually black (excluding desert southwest form). Uppersurface of both sexes primarily black; male with a yellow postmedian band, both sexes with submarginal row of small rounded yellow spots; hindwing with black pupil centered or reaching inner margin in red-orange eyespot at anal angle, female also with iridescent blue submarginal patch. Hindwing undersurface postmedian spot rows with at least some orange; abdomen with two or three longitudinal rows of yellow spots.

One flight, late may to late June in the north, late June to mid-August in Colorado mountains; several flights late April to September in lowland Colorado, February to October in southern California; many flights all year in Florida (Scott 1986). February to October across southwestern US, mainly May to September to the north (Glassberg 2001). May to early September in the Rocky Mountain states (Ferris and Brown 1981), late May to late October throughout Colorado (Scott and Scott 1978), late June to late August in the mountains of central Colorado (Emmel 1964; Scott and Scott 1978).

Best determined by a combination of wings mostly black (excluding desert southwest form), uppersurface with submarginal row of small rounded yellow spots, hindwing with black pupil centered or reaching inner margin in red-orange eyespot at anal angle; hindwing undersurface postmedian spot rows with at least some orange; abdomen with two or three longitudinal rows of yellow spots.

Non-migratory.

Gardens, hayfields, pastures, foothills, deserts, forest openings, other open habitats including above treeline (Scott and Scott 1978; Ferris and Brown 1981; Feeny et al. 1985; Scott 1986; Opler and Wright 1999; Glassberg 2001). Habitat in Montana not described but probably similar.

Larval food plants mainly various native and introduced members of the Apiaceae, including Aegopodium, Angelica (multiple species), Anethum, Apium, Berula, Carum, Cicuta (multiple species), Conium, Crytotaenia, Cymopterus, Daucus, Foeniculum, Harbouria, Heracleum, Levisticum, Ligusticum, Osmorhiza, Oxypolis, Pastinaca, Petroselinum, Ptilimnium, Sium, Spermolepis, Taenidia, Tauschia, Thaspium, and Zizia, also members of the Rutaceae including Dictamnus, Ruta, and Thamnosma (Emmel 1964; Scriber and Finke 1978; Scott 1986, 1992, 2006). Adults feed on flower nectar, including Agoseris, Asclepias, Astragalus, Baccharis, Bidens, Buddleja, Carduus, Castilleja, Cephalanthus, Chrysothamnus, Cirsium, Cleome, Conium, Delphinium, Dianthus, Dipsacus, Echinacea, Eriogonum, Erysimum, Euphorbia, Helianthus, Hemerocallis, Heterotheca, Krigia, Liatris, Lobelia, Lythrum, Medicago, Melilotus, Monarda, Nepeta, Oxytropis, Penstemon, Phlox, Prunus, Ribes, Scutellaria, Sedum, Senecio, Solidago, Stachys, Symphyotrichum, Syringa, Trifolium, Verbena, Vicia, and Zinnia (Tooker et al. 2002; Scott 2014).

Females lay eggs singly on host plant leaves (both surfaces) and inflorescences (Scott 1986, 1992, 2006). About 30-50 eggs laid/day, 200-900/lifetime over a 13 day period, eggs hatch in 6-8 days, develop to L5 instar and pupae in about 15-23 days, adults eclose (emerge) from pupae in about 11-12 days (Blau 1981; Feeny et al. 1985; Scott 1986); in multibrooded populations, overwinter (hibernate) as pupae (Scott 1979; Feeny et al. 1985). Larvae feed on host leaves and inflorescences, build no nests, pupate above ground on grasses, weedy stems, rocks, posts (West and Hazel 1979; Scott 1986). Males patrol and perch throughout the day, often on hilltops, awaiting and searching for females, and may be territorial (Scott 1975b, 1986; Lederhouse 1982; Feeny et al. 1985).