Montana Field Guide

[From Ferris and Brown 1981; Scott 1986; Glassberg 2001; Pyle 2002] Forewing 2.0-2.5 cm. Upperwings predominantly black on the basal 2/3, with red and white spot-bands, a distinctive orange-red submarginal band across the predominately dark-brown to black wings; underwings with alternating bands of cream and bright brick-red with black veins and borders of spot-bands.

One flight; mostly late June to July (late July to mid-August for subalpine sites), with a short flight season (Scott 1986; Glassberg 2001); mid-June to late July in British Columbia (Guppy and Shepard 2001); June to mid-August (Williams et al. 1984).

The orange-red submarginal band across the predominately dark-brown to black forewings and hindwings is distinctive.

Non-migratory.

Montane areas in wet meadows, marshy sites, along small streams, open riparian habitat; tree canopy predominantly lodgepole pine, Engelmann spruce, subalpine fir, sometimes with willow, cottonwood, aspen, often in fire-disturbed locations (Williams et al. 1984; Scott 1986; Williams 1988, 1995; Guppy and Shepard 2001). Habitat in Montana as described above (Williams 1988); in Glacier National Park, reported in montane mesic meadows and woodlands (Debinski 1993).

Larval food plants predominantly Lonicera involucrata and to a lesser extent Valeriana occidentalis (Williams et al. 1984; Williams and Bowers 1987). Oviposition reported on other plant species, including Castilleja, Pedicularis, Symphoricarpus, and Veronica; larvae feed on Plantago in captivity (Scott 1986; Williams 1988). Adults feed on flower nectar (including Achillia, Agoseris, Antennaria, Arnica, Aster, Chrysanthemum, Cirsium, Geranium, Geum, Helianthella, Heracleum, Polygonum, Potentilla, Rosa, Saxifraga, Senecio, Solidago, Valeriana) and mud (Williams 1988, 1995; Scott 2014).

Females lay eggs in masses on the undersides of host plant green leaves that tend to intercept morning sun; Wyoming masses in the Beartooth Mountains average 146 eggs (23-310 eggs), masses in the Teton Mountains average 130 eggs. Egg loss from masses ranges from 13-30%. Eggs hatch from July to September, 23-45 days after laying. Newly emerged larvae shortly migrate to the upper surface of leaves where they form a communal feeding web and remain together overwinter. Diapause (overwintering) can occur in L2-L4 instars, depending on duration prior to onset of winter. Larvae terminate diapause shortly after spring snow melt (late May to mid-June); most larvae diapause a second winter as L5 before pupating. L5 instars move away from host plants and pupate within 50 cm of the ground; pupation to adult emergence requires about 21 days (Williams 1981; Williams et al. 1984). Males patrol near conifer tree tops in search of females, and mating typically occurs in or near the tops of trees.