Montana Field Guide

Two basic but variable phenotypes, the taxonomy still in flux (see for example Mullen et al. 2008).

[From Ferris and Brown 1981; Scott 1986; Opler and Wright 1999; Glassberg 2001; Pyle 2002]
Limenitis arthemis arthemis (WHITE ADMIRAL); Forewing 2.9-3.7 cm. Wing margins scalloped, uppersurface black; forewing with outwardly curved broad white median band and a few apical white spots, hindwing with postmedian white band, submarginal series of red spots, marginal row of blue dashes; undersurface reddish-brown with white bands and spots as on uppersurface, 2-3 large reddish-orange spots near dark wing bases.

Limenitis arthemis astyanax (RED-SPOTTED PURPLE); Forewing 3.5-4.8 cm. Wing margins scalloped, uppersurface blue to blue green, outer portion of hindwing more iridescent; undersurface of forewing pale orangish apical region and iridescent blue in the basal half, forewing with 2 large reddish-orange costal spots near dark wing base, hindwing with 3 reddish-orange spots near dark wing base and a submargional series of reddish-orange spots.

One flight in the north, mid-July to mid-August in Labrador and mid-June to mid-August in southern Saskatchewan; one flight mid-June to mid-July and partial second flight in August in Ontario; two flights, June to September in New York; many flights in the south, march to November in Florida and April to November in Arizona (Scott 1986). Late May to early Septmber, mainly mid-June to mid-August (Glassberg 2001).

White Admiral best determined by a combination of the bold white bands, the uppersurface hindwing with submarginal series of red spots and marginal row of blue dashes, undersurface of wings with 2-3 large reddish-orange spots near dark wing bases.

Red-spotted Purle best determined by a combination of the uppersurface blue to blue green, outer portion of hindwing more iridescent, the forewing undersurface with 2 large reddish-orange costal spots near dark wing base, hindwing with 3 reddish-orange spots near dark wing base and a submargional series of reddish-orange spots.

Non-migratory.

Moist deciduous broadleaf woodlands, evergreen oak-pine forest, mixed evergreen forest, forest edges, clearings, orchards, glades, streambanks (Ferris and Brown 1981; Opler and Wright 1999; Glassberg 2001; Pyle 2002). In Glacier National Park, Montana reported from montane mesic meadows (Debinski 1993).

Larval food plants for the northern arthemis subspecies include Alnus, Amelanchier, Betula, Carpinus, Crataegus, Fagus, Malus, Populus, Prunus, Salix, Tilia, and Ulmus; larval food plants for the southern and eastern astyanax subspecies include Carpinus, Crataegus, Cydonia, Malus, Populus, Prunus, Pyrus, Quercus, Salix, and Tilia (Ferris and Brown 1981; Scott 1986). Adults feed on flower nectar (including Aster, Eutrochium, Rhus), sap, rotting fruit, carrion, dung, honeydew, cercopid spittle, decaying wood, mud (Voss 1954; Reed 1958; Downes 1973; Scott 1986; Lederhouse 1993; Wise 2010).

Females lay eggs singly on the uppersurface of host plant leaf tips (Scott 1986; Guppy and Shepard 2001). Following egg-hatch larvae build no nest but eventually create a leaf-tip silk-bound hibernaculum and overwinter as L3 instar, rarely L2 or L4 (Scott 1979, 1986), although in British Columbia hibernation by L2 instar may be more prevalent (Guppy and Shepard 2001). Post-diapause larve develop through L4-L5 and pupate (second generation males as L4, females as L5); pupae suspended from base (Guppy and Shepard 2001; Pyle 2002). Males territorial mid-day through afternoon, perch >80 % of time on trees and tall bushes 1-3 m above ground along flyways, patrol < 15% of time while awaiting passage of females (Scott 1983; Lederhouse 1993; Guppy and Shepard 2001); in Arizona and Texas, males patrol throughout the day near host plants, sometimes on hilltops (Scott 1975b, 1986).