Callophrys [Mitoura] gryneus
Juniper Hairstreak

Family Description:
Alternate Common Names:Cedar Hairstreak, Olive Hairstreak.
Note: This species includes several subspecies such as barryi and loki. The delineation between this species and Callophrys [Mitoura] siva are debated by scientists.


Caterpillar: The caterpillar is green and marked along each side with white or yellow diagonal dashes.
Adult: The butterfly is small, with a wingspan of 7/8 to 1 1/16 inches, and has a thin "tail" extending from the hindwing. Typically, the male is dark brown on the upperside and possibly tinged with orangish to golden brown. The female is brown to golden brown on the upperside. Underneath, both sexes are most commonly bright to yellowish green, though in some populations the underside may be brownish. The underside of the forewing is marked with a vertical line of connected white dashes, edged towards the inside with brown. The underside of the hindwing is marked two white dashes or spots near the base of the wing, and a wavy, vertical white line down the center. The spots and the wavy line may be edged with reddish brown on one side. The outer edge of the underside of the hindwing may have several black spots, a white edging, and a faint orangish spot on a clouded region of blue near the tail.

This species ranges from southern British Columbia south to southern California, throughout the western and southwestern U.S., extending east to the east coast but absent from both the extreme northern and southern edges of the U.S. It occurs throughout Idaho.

It occurs in forests and open woodlands.


Caterpillar: Caterpillars feed on the tips of foliage of eastern red cedar and juniper belonging to the genus Juniperus.
Adult: Butterflies drink flower nectar.

There is one to two generations of caterpillars each summer. Each undergoes five to seven stages of growth, called instars. The caterpillar is equipped with a honey gland, also known as a dorsal nectary organ, which emits a sugary solution agreeable to ants. The ants feed on the solution and in turn protect the caterpillar from predators. The caterpillars are colored in such a way that they mimic the foliage tips of their host plant. Pupae overwinter in a physiological state called diapause. Adults generally fly from May to August. The thin "tail" on each of the hindwings of adults is thought to mimic insect antennae and thus misleads bird predators into biting at the wrong end and only getting a mouthful of wing, while the butterfly escapes in the other direction.

Males perch in host trees to wait for receptive females. Eggs are laid singly on the tips of host plant foliage.

Idaho Status: Unprotected nongame species.
Global Rank: G5
populations levels are secure, but may be of concern in the future.

Ballmer, G. R. and G. F. Pratt. 1988. A survey of the last instar larvae of the Lycaenidae of California. Journal of Research on the Lepidoptera 27:1-81.

Ferris, C. D. and F. M. Brown. (eds.) 1981. Butterflies of the Rocky Mountain States. Univ. of Oklahoma Press, Norman, Oklahoma, USA, 442 pp.

Opler, P. A., H. Pavulaan, and R. E. Stanford. 1995. Butterflies of North America. Jamestown, North Dakota, USA: Northern Prairie Wildlife Research Center Home Page. (Version 05Nov98).

Opler, P. A. and A. B.Wright. 1999. A Field Guide to the Western Butterflies.   Second Edition.  Peterson Field Guide Series. Houghton Mifflin Company, New York, New York, USA, 540 pp.

Pyle, R. M. 1981. National Audubon Society Field Guide to North American Butterflies. Alfred A. Knopf, Inc., New York, New York, USA, 924 pp.

Scott, J. A. 1986. The Butterflies of North America. Stanford University Press, Stanford, California, USA, 583 pp.

Stanford, R. E. and P. A. Opler. 1993. Atlas of Western U.S.A. Butterflies (Including Adjacent Parts of Canada and Mexico). Published by authors, Denver, Colorado, USA, 275 pp.