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Montana Field Guide

Montana Field Guides

Thicket Hairstreak - Callophrys spinetorum

Native Species

Global Rank: G5
State Rank: S5

Agency Status

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General Description
[From Ferris and Brown 1981; Scott 1986; Opler and Wright 1999; Glassberg 2001; Pyle 2002] Forewing 1.4-1.5 cm. Double-tailed (posterior tail longer, both white-tipped), fringes white. Upperside steel-blue with faint iridescent sheen, broad black borders; underside reddish brown, forewing with a white cell-end bar, hindwing with a continuous white postmedian band edged inwardly with black and forming a W near tails, usually with a series of small black submarginal points or chevrons with orange caps and blue bottoms.

One flight, mostly June northward; several flights, March to August southward (Scott 1986). May to July in one flight areas, March to September in two flight areas (Glassberg 2001). Early May to late July in Colorado (Scott and Scott 1978), late April to late August in Oregon and Washington (Pyle 2002), early May to mid-August in Oregon (Warren 2005), late April to mid-July in British Columbia (Guppy and Shepard 2001).

Diagnostic Characteristics
Best determined by combination of reddish-brown undersurface combined with steel-blue uppersurface, presence of tails, undersurface of hindwing with a white postmedian band forming a W near tails, usually with a series of small black submarginal points or chevrons with orange caps and blue bottoms.

Species Range
Montana Range Range Descriptions


Range Comments
Southern British Columbia and Alberta south to northern Baja California and northern Sierra Madre of western Mexico, east to eastern Montana, Colorado, New Mexico, and western Texas (Scott 1986; Opler and Wright 1999; Glassberg 2001); 1830 m to 3050 m elevation in the Rocky Mountain states (Ferris and Brown 1981), 1890 m to 3353 m elevation in Colorado (Brown 1957; Shields 1965; Scott and Scott 1978), 427 m to at least 2134 m elevation in Oregon (Warren 2005), up to 1000 m elevation in British Columbia (Threatful 1988; Guppy and Shepard 2001). In Montana, 853 m to 2355 m elevation in the mountainous western 1/3 of the state (Shields 1965; Kohler 1980; Stanford and Opler 1993; FLMNH Lepidopterists' Society database). Uncommon to common in most of the Rocky Mountains, rare west of the Rockies and in Alberta (Glassberg 2001).

Observations in Montana Natural Heritage Program Database
Number of Observations: 2

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



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


Foothill and montane conifer forest, low to high elevation forest clearings, roadsides (Opler and Wright 1999; Glassberg 2001; Guppy and Shepard 2001; Pyle 2002). In Glacier National Park, Montana reported from montane wet meadows (Debinski 1993); other Montana localities include several in montane mixed-conifer forest (Shields 1965).

Food Habits
Larval food plants include several species of Arceuthobium, which are parasitic on species of Pinaceae (Shields 1965; Scott and Scott 1978; Ferris and Brown 1981; Scott 1986; Pyle 2002; Warren 2005). Adults feed on flower nectar (including Achillea, Allium, Anaphalis, Antennaria, Arctostaphylos, Asclepias, Berberis, Ceanothus, Cymopterus, Erigeron, Eriodictyon, Eriogonum, Fragaria, Helenium, Iris, Lomatium, Lupinus, Melilotus, Polygonum, Potentilla, Prunus, Pseudocymopterus, Rhus, Ribes, Sedum, Taraxacum, Salix, Sambucus, Senecio, Solidago, Spraguea) and mud (Shields 1965; James and Nunnallee 2011; Scott 2014).

Reproductive Characteristics
Females lay eggs singly in deep crevices on host plant (Scott 1986; James and Nunnallee 2011). Eggs hatch in about 7 days (depending on temperature), develop from L1 instar to L4 instar and pupate in about 29 days. Pupae overwinter in trees; some adults may eclose (emerge from pupae) in about 21 days without overwintering as pupae (Scott 1979; Pyle 2002; James and Nunnallee 2011). Larvae solitary, feed on host buds and fruiting heads, may be tended by ants (Formica pilicornis in captivity), build no nests (Scott 1986; Ballmer and Pratt 1991; James and Nunnallee 2011). Males perch throughout the day, especially in the crowns of hilltop trees, to await females (Scott 1975b, 1986).

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Citation for data on this website:
Thicket Hairstreak — Callophrys spinetorum.  Montana Field Guide.  .  Retrieved on , from