Satyrium behrii

Distinguished from other Satyrium species by combination of geographic range (western North America), habitat preference (dry slopes and canyons), and association with specific larval host plants (Purshia and Cercocarpus species). The single annual generation in June–July helps separate it from sympatric species with different flight periods. Subspecies S. b. columbia occurs in British Columbia, S. b. crossi in more southern areas.

Small butterfly with wingspan 24–32 mm. Typical hairstreak morphology with thin, hair-like tail projections on the hindwings. Upper wing surfaces generally gray-brown with orange marginal spots on hindwings. Undersurfaces have fine striations and small spots characteristic of the genus.

Dry slopes and canyons in western North America. Associated with pinyon-juniper woodland, sagebrush steppe, and open montane habitats where larval host plants occur. Found from low elevations to moderate mountain slopes.

Western North America from western Texas north and west through New Mexico, Arizona, and southern California to British Columbia. Three recognized subspecies with somewhat discrete geographic ranges: S. b. behrii (southwestern), S. b. columbia (British Columbia), and S. b. crossi (intermediate areas).

Adults active June to July. Single generation per year (univoltine). Larval stage occurs through late summer and winter, with pupation in spring.

Adults feed on flower nectar. Larvae are obligate feeders on Purshia tridentata (antelope bitterbrush), Purshia glandulosa (desert bitterbrush), and Cercocarpus montanus (alderleaf mountain mahogany)—all in family Rosaceae.

• Purshia tridentata - larval hostAntelope bitterbrush; primary host plant
• Purshia glandulosa - larval hostDesert bitterbrush; secondary host
• Cercocarpus montanus - larval hostAlderleaf mountain mahogany; secondary host

Complete metamorphosis with single annual generation. Eggs laid on host plant. Larvae feed on host foliage, likely overwintering as partially grown larvae or pupae. Adults emerge in early summer (June–July), mate, and lay eggs to complete the cycle.

Adults have been observed visiting flowers of Hymenopappus filifolium (fineleaf woollywhite) in sand dune habitats. Typical hairstreak behavior includes perching with wings closed, rubbing hindwings together to draw attention to false eye spots near the tail, and rapid, darting flight when disturbed.

Pollinator as adult; herbivore as larva. Part of food web supporting predators and parasitoids. Host plant specificity suggests potential role as indicator species for healthy stands of Purshia and Cercocarpus.

Subject of butterfly watching and photography. No significant economic importance. Conservation concern in some areas due to habitat loss and alteration of fire regimes affecting host plant communities.

• Satyrium tetraOverlaps in range; distinguished by different host plant associations and often bivoltine flight pattern
• Callophrys gryneusJuniper hairstreak; similar size and habitat but uses Juniperus as larval host and has different wing pattern
• Other Satyrium speciesMany western Satyrium require close examination of genitalia or larval host association for definitive identification

• butterfly
• hairstreak
• Lycaenidae
• western North America
• Purshia
• Cercocarpus
• univoltine
• dry slopes
• canyons
• pollinator
• herbivore

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• Eumastacidae | Beetles In The Bush