This species ranges from southern British Columbia and Alberta south through the western U.S. to California and northern Arizona and New Mexico. A small portion of its range extends into western South Dakota and northwestern Nebraska. In Idaho, it occurs in the panhandle and central portions of the state.
This species can be found in coniferous forests.
Caterpillars feed on the needles of a variety of conifers including pines (Pinus
spp.), firs (Abies spp.), and Douglas-fir (Pseudotsuga menziesii).
Adult: Butterflies drink flower nectar, often from yellow flowers belonging to the sunflower family (Asteraceae), such as from rabbitbrush (Chrysothamnus spp.).
Eggs overwinter and hatch in the spring. There is one generation of caterpillars each year. Young caterpillars feed in groups; occasional outbreaks of caterpillars can result in the defoliation of conifer stands. Caterpillars may pupate on bark, twigs, or on vegetation of the forest floor. One researcher found that pupae on bark or twigs were brown while pupae on vegetation were green; another researcher attributes pupal color to sex. Adults generally fly from late June through September. They can be seen flying among the treetops in the afternoon. This is the only white butterfly found in stands of pines in most of the U.S., except in parts of Arizona where there may be additional species of white butterflies in conifer forests.
Males patrol in search of receptive females. Females lay green eggs in tight rows on conifer needles.
|Idaho Status:||Unprotected nongame species.|
G5; populations are widespread, abundant, and secure.
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. http://www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/bflyusa.htm (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.