Montana Field Guide

Taxonomy of western North American Anthocharis sara complex is in flux, with some authorities elevating the subspecies stella and julia to full species, but using inconsistent ranges among treatments. Other authorities use the species name julia for this taxon in Montana and consider stella a subspecies of julia restricted to the California Sierra Nevada (the subspecies in Montana being A. j. julia). Yet other authorities retain sara as the full species name for these subspecies for now, with julia the Montana subspecies (Kohler 1980; Geiger and Shapiro 1986; Scott 1986; Opler and Wright 1999; Glassberg 2001; Guppy and Shepard 2001; Pyle 2002; Warren 2005; Scott et al. 2008). Most recently (February 2017), the species present in Montana is considered to be A. sara, with the subspecies in western Montana designated as A. s. sulphuris (S. Kohler pers. comm.), possibly with julia as the subspecies in central Montana; the name stella should not be applied to any populations in the state. Sections of this account probably include information for more than one taxon now considered by some as a full species. [See also the account for Pacific Orangetip (Anthocharis sara)]

[From Ferris and Brown 1981; Scott 1986; Opler and Wright 1999; Glassberg 2001; Pyle 2002] Forewing 1.6-2.3 cm. Uppersurface of both sexes with orange forewing tip (bright orange in Pacific male, paler in "Stella" male), male base color white to cream-white, female pale yellow, both sexes with variable black barring on forewing framing orange patch, females with pale yellow capping the orange patch outwardly. Undersurface marbling on forewing and hindwing granular and yellow-green, with yellow along veins.

One flight, March to June (Scott 1986). February to early April in south, March to mid-July in Pacific Norhtwest, mid-July to mid-August in mountains, May to July in Colorado (Glassberg 2001). March to early August in the Rocky Mountain region (Ferris and Brown 1981), late May to late June in southcentral Colorado (Scott and Scott 1978), mid-March to mid-August in Oregon and Washington (Pyle 2002), late February to mid-August (Warren 2005), late April to August in British Columbia (Threatful 1988; Guppy and Shepard 2001).

Unmistakable. Best determined by combination of orange patch on forewing tips, white to pale-yellow base color, yellow-green marbling with yellow veins on hindwing undersurface.

Non-migratory.

Open habitats, ponderosa/lodgepole pine forest, montane meadows, foothill canyons, sagebrush steppe, roadsides, old fields, grasslands, above treeline in alpine tundra (Shapiro 1977; Scott 1986; Opler and Wright 1999; Glassberg 2001; Pyle 2002; Warren 2005; Scott et al. 2008). In Glacier National Park, Montana reported (as A. sara) from transition areas between open and forested habitat (Debinski 1993); in the Greater Yellowstone Ecosystem, reported (as A. sara stella) from aspen woodlands and meadows (Debinski and Pritchard 2002).

Larval food plants are various native and exotic mustards, including Arabis (multiple species), Athysanus, Barbarea (several species), Brassica (multiple species), Cardamine, Caulanthus, Erysimum, Capsella, Dentaria, Descurainia, Hirschfeldia, Raphanus, Sinapis, Sisymbrium, Streptanthus (several species), Thysanocarpus, and Tropaeolum (Ferris and Brown 1981; Scott 1986, 1992; Guppy and Shepard 2001; Graves and Shapiro 2003; Warren 2005; James and Nunnallee 2011). Adults feed on flower nectar (including Amsinckia, Collinsia, Erigeron, Frageria, Mimulus, Phlox, Taraxacum) and mud (Pyle 2002; James and Nunnallee 2011; Scott 2014).

Females lay eggs singly on underside of host plant leaves and inflorescences, larval found on all parts of host plant, including stems and fruits; female may lay about 100 eggs over two days (Scott 1986, 1992; James and Nunnallee 2011). Eggs hatch in about 3-4 days (depending on temperature), develop to L5 instar in about 16-20 days, larvae wander before pupation on vertical stick away from host plant. Larvae solitary, build no nest, overwinter as pupae, some pupae may take 2-3 years before producing adults (Scott 1979, 1986; James and Nunnallee 2011). Males patrol throughout the day in valley bottoms and hillside draws in search of females (Scott 1975b, 1986).