Callophrys xami

Distinguished from similar hairstreaks by the sharp W-shaped mark in the postmedian white band on the hindwing underside. Juniper Hairstreak (Callophrys gryneus) lacks this sharp W mark; Silver-banded Hairstreak has a broader, more diffuse silver-white postmedian line. The combination of tailed hindwings, yellowish-green ground color, and precise W-shaped white line is diagnostic.

Small tailed butterfly with wingspan 2.38–2.86 cm. Underside of hindwing yellowish-green with a postmedian white line forming a distinct W-shape toward the tails. Upperwing surfaces not described in sources. False head pattern on hindwing posterior created by color markings. Eggs spherical, slightly flattened, 0.7–0.8 mm diameter, pale green fading to white. First instar larvae 0.8–1.0 mm, pale yellow with brown head, covered in tiny brownish hairs. Second instar yellow-green to pale pink with pinkish-red hairs. Final instar larvae approximately 16 mm, yellowish-green with pale yellow head, dark hairs. Pupae 9–11 mm, variable brown to reddish-brown or black, with two small pale brown spines at abdominal tip.

Coniferous woodland forests and sunny areas along mountain and canyon slopes that provide partial shade. Cool to warm temperate climate zones.

Southern Arizona, central and southern Texas, south through Mexico to Guatemala. Greatest abundance near Mexico City reported July–September.

Multiple flight periods annually, generally March through December. Primary flight June and September–December. In Mexico City region: peak July–September, secondary peak December–January, minor peak April–May.

Larvae feed on Crassulaceae host plants, primarily Echeveria and Sedum species. Adults: feeding habits not documented in sources.

• Echeveria gibbiflora - larval host plantprimary host in Mexico
• Sedum allantoides - larval host plantprimary host in Mexico
• Echeveria - larval host plantgenus-level association
• Sedum - larval host plantgenus-level association

Egg stage approximately 7 days. Eggs deposited on underside of host plant leaves. Larvae pass through at least three instars, potentially four or five; precise duration unknown. Pupal stage variable in coloration and size. Multiple generations annually corresponding to flight periods.

Males defend territories for mating and resource access, with frequent territory shifts and aggressive displacement of intruding males. Courtship involves male perching on host plant, pursuing passing females, and aerial courtship flight lasting approximately 30 seconds. Male flutters wings aggressively while female remains still with wings closed during perched courtship. Copulation may last several hours. Polygynous mating system with multiple matings per individual. Perches with wings closed, displaying false head pattern on hindwing posterior.

Herbivore on Crassulaceae; specific ecosystem role not documented.

Considered a very rare species of conservation interest. No documented economic impact.

• Callophrys gryneusJuniper Hairstreak lacks the sharp W-shaped mark in the postmedian white band; postmedian line straighter or less angular
• Callophrys (silver-banded hairstreak group)Silver-banded Hairstreak has broader, more diffuse silver-white postmedian line rather than sharp W-shape

• butterfly
• hairstreak
• Lycaenidae
• false head
• territoriality
• Crassulaceae
• Southwestern United States
• Mexico
• Guatemala

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Bug Eric: Year-end Wrap-up
• Bug Eric: City Nature Challenge 2023 Recap
• Platystomatidae | Beetles In The Bush
• The courtship behavior of Callophrys xami (Lycaenidae)
• False heads and sexual behaviour in a hairstreak butterfly, Callophrys xami (Lepidoptera: Lycaenidae)
• Lack of evidence that the false head of male Callophrys xami (Reakirt, 1867) (Lepidoptera, Lycaenidae) is a sexually selected trait