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Montana Field Guide

Montana Field Guides

Pearl Crescent - Phyciodes tharos

Native Species

Global Rank: G4G5
State Rank: S5


Agency Status
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General Description
[From Ferris and Brown 1981; Scott 1986; Opler and Wright 1999; Greenberg 2001] Forewing 1.5-2.0 cm. Variable, usually with orange antennae clubs. Uppersurface with thick black borders but middle more broadly orange, males with postmedian and submarginal orange areas broken by fine black marks, forewing median band usually not much paler than postmedian band, hindwing of males and females similar; undersurface of hindwing with crescent surrounded by brownish patch.

Phenology
Several flights in the south and east; late April to October in Virginia, May to September in New York and Colorado plains; two flights in Saskatchewan, late May to August (Scott 1986). April and May to September and October (Glassberg 2001).

Diagnostic Characteristics
Probably best told by a combination of orange antennae clubs, uppersurface with thick black borders but middle more broadly orange, the forewing median band usually not much paler than postmedian band, hindwing of males and females similar; undersurface of hindwing with crescent surrounded by brownish patch. Similar to P. cocyta, with which it may be be easily confused.

Species Range
Montana Range Range Descriptions

Native
 


Range Comments
Extreme southern Canada from southeastern Alberta east to southern Ontario, south through eastern 2/3 of US east of continental divide, southwest to northern Baja and southern Mexico; isolated populations in eastern Utah and western Colorado (Scott 1986; Opler and Wright 1999; Glassberg 2001); to 2926 m elevation in Colorado (Brown 1957; Scott and Scott 1978). In Montana, reported from most counties in the eastern 2/3 of the state, and at least Flathead County west of the continental divide (Kohler 1980; Stanfrod and Opler 1993). Common to abundant (Glassberg 2001).

Observations in Montana Natural Heritage Program Database
Number of Observations: 6

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density

Recency

 

(Observations spanning multiple months or years are excluded from time charts)



Migration
Non-migratory.

Habitat
Prairies, intermittent streamcourses, riparian canyons, wooded marshes, open weedy fields, vacant lots, pastures, roadsides (Ferris and Brown 1981; Scott 1986; Opler and Wright 1999; Glassberg 2001). In Glacier National Park, Montana reported in montane xeric and mesic meadows (Debinski 1993).

Food Habits
Larval food plants include several species of Symphyotrichum, captive larvae also feed on Erigeron (Scott 1986, 1992, 2006). Adults feed on flower nectar (including Asclepias, Astragalus, Bidens, Cirsium, Cornus, Echinacea, Euphorbia, Fragaria, Gaillardia, Helenium, Helianthus, Heracleum, Heterotheca, Lithospermum, Machaeranthera, Medicago, Nepeta, Phlox, Prunus, Pycanthemum, Ranunculus, Rudbeckia, Senecio, Solidago, Symphyotrichum, Taraxacum, Trifolium, Valeriana, Verbena, Viola) and mud (Scott 1986, 2014; Tooker et al. 2002).

Reproductive Characteristics
Females lay eggs laid in clusters (20-300 eggs per cluster) on undersides of host plant leaves, up to 700 eggs total per female. Larvae gregarious, build no nest, overwinter (hibernate) as L3 instar (Scott 1986, 1992, 2006). Males patrol throughout the day near host plants, mostly in valley bottoms, wet meadows, streamsides, in search of females (Scott 1975b, 1986).

References
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Citation for data on this website:
Pearl Crescent — Phyciodes tharos.  Montana Field Guide.  .  Retrieved on , from