For a key to the terms used see Lepidopteran glossary
The Juniper Hairstreak has many subspecies or races, some of which may even be separate species. The upper side of the "Olive" Juniper Hairstreak (Callophrys gryneus gryneus) is tawny orange or a bronzy color in males, and blackish brown in females. The underside of the wings is bright green with a variable amount of brown scaling. There are two white postbasal spots and a white zigzag postmedian line edged inward with brown on the hind wing.
The "Siva" Juniper Hairstreak (Callophrys gryneus siva) is also similar to the gryneus race. It lacks the postbasal spots, the postmedian line is straight, and some individuals are brown. Intermediates of the gryneus and siva races occur in west Texas and New Mexico.
The underside of "Nelson's" Juniper Hairstreak (Callophrys gryneus nelsoni) is brown with a violet sheen; the white postmedian line is faint, sometimes partial or absent; and the postbasal spots are lacking.
"Muir's" Juniper Hairstreak (Callophrys gryneus muiri) is similar to the nelsoni race except the underside of the wings are a darker brown with a purplish-greenish tint, and the postmedian line is partial to complete.
"Thorne's Juniper Hairstreak (Callophrys gryneus thornei) is quite similar to the loki race except it usually lacks green more often being a violet-brown to a brownish-gray color.
The Hessel's Hairstreak (Callophrys hesseli) is the only similar species in the Juniper Hairstreak's range. The Hessel's Hairstreak is similar to the gryneus and sweadneri races. It is often more of a blue-green color, the postmedian line is edged with brown on both sides, and it has a white spot near the fore wing costa.
Both sexes visit flowers near the host plant, especially the sweadneri race.
Males are highly territorial on cedar trees, where they perch in search of females. Often, males can be set in flight by gently shaking the trees. Females lay their eggs singly at the tip of host plant leaves. The eggs are pale green with white ridges. The larvae are vivid green with a faint middorsal stripe that begins at the thorax and runs down the abdomen. Whitish-yellow spots occur on either side of the middorsal stripe. A whitish-yellow subspiracular stripe (sometimes broken between segments) runs the length of the body. The chrysalis of the gryneus race is brown to pale brown and is mottled with black with the abdomen being a bit reddish. Chrysalids of western races are dark brown. The Juniper Hairstreak overwinters as a chrysalis. The gryneus race has 2 broods per year; sweadneri, 2 broods per year; siva, 2-3 broods per year; nelsoni, 1 brood; muiri, 1 brood; loki, 1-2 broods; and the thornei race has 1 brood per year.
Here is a list of host plants used by the Juniper Hairstreak:
- Eastern Redcedar, Juniperus virginiana (Used by the gryneus and sweadneri races.)
- Southern Redcedar, Juniperus silicicola (Used by the gryneus and sweadneri races.)
- California Incense-cedar, Calocedrus decurrens (Used by the nelsoni race.)
- Western Redceder, Thuja plicata (Used by the nelsoni race.)
- Sargeant's Cypress, Cupressus sargentii (Used by the muiri race.)
- Tecate Cypress, Cupressus forbesii (Used by the thornei race.)
- Common Juniper, Juniperus communis (Used by the siva race.)
- Alligator Juniper, Juniperus deppeana (Used by the siva race.)
- Utah Juniper, Juniperus osteosperma (Used by the siva race.)
- Rocky Mountain Juniper, Juniperus scopulorum (Used by the siva race.)
- Ashe Juniper, "Juniperus ashei" (Used by the gryneus race.)
- California Juniper, Juniperus californica (Used by the siva and loki races.)
- ^ a b c d e f Rich Cech & Guy Tudor (2005). Butterflies of the East Coast. Princeton University Press, Princeton, New Jersey. ISBN 0-691-09055-6
- ^ a b c d e f g h Jim P. Brock & Kenn Kaufman (2003). Butterflies of North America. Houghton Mifflin, New York NY. ISBN 0-618-15312-8
- ^ a b c d e f James A Scott (1986). The Butterflies of North America. Stanford University Press, Stanford, California. ISBN 0-8047-2013-4
- ^ David L. Wagner (2005) Caterpillars of Eastern North America. Princeton University Press, Princeton, New Jersey. ISBN 0-691-12143-5
- ^ Bob Stewart, Priscilla Brodkin and Hank Brodkin (2001). Butterflies of Arizona. West Coast Lady Press