Alternate Common Names:Mistletoe Hairstreak, Brown Mistletoe Hairstreak.
This species ranges from southern British Columbia south to central California, and an isolated population occurs from northeastern Oregon into central Idaho.
It occurs most commonly in thick coniferous forests and occasionally in other woodlands.
Caterpillar: Caterpillars feed on the external parts of dwarf mistletoes (Arceuthobium spp.), a parasitic plant that lives on a variety of conifers.
Adult: Butterflies drink flower nectar and may obtain additional moisture and salts from mud.
There is one generation of caterpillars each summer in most of its range, but there may be two in parts of California. Each caterpillar undergoes five 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. Pupae overwinter in a physiological state called diapause. Adults generally fly from February through August. Butterflies tend to fly high up in the forest canopy. 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. This species has undergone large fluctuations in its numbers since the mid-1900s, from being very rare to very common to currently being quite rare again.
Males perch to wait for receptive females. Eggs are laid on mistletoes.
|Idaho Status:||Unprotected nongame species.|
vulnerable to population decline and extinction.
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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.
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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.