Pontia beckerii
Becker’s White

Family Description:
Alternate Common Name: Sagebrush White.
Caterpillar: The caterpillar is light green, ringed with yellow, and dotted with black.
Adult: The butterfly is medium-sized, with a wingspan of 1 to 2 inches. It is white on the upperside. The forewing has a large black spot with a white center, and black markings at the tip and along the edge. Females may have black spots on the hindwing, as well. Underneath, the forewing is whitish; the spot from above shows through as black, while the other markings show through as grayish green. The underside of the hindwing is marbled with grayish green at the base while the outer edge is striped.

This species ranges from southern British Columbia and western Montana south to southern California and northern Arizona and New Mexico, extending east as far as western South Dakota and eastern Colorado. It occurs through most of Idaho.

It can be found in dry, often hot habitats, such as sagebrush steppe, desert foothills, and canyons.


Caterpillar: Caterpillars feed on various parts of members of the mustard family (Brassicaceae), including mustards (Brassica spp.) and hedge mustards (Sisymbrium spp.), and bladderpod (Isomeris arborea) of the caper family (Capparidaceae).
Adult: Butterflies drink flower nectar.

There are generally two generations of caterpillars each year, and possibly more in the south. Pupae from the last generation of the year overwinter in a physiological state called diapause. Adults generally fly from March to October.

Males actively patrol in search of receptive females. Females lay eggs singly on all parts of host plants.

Idaho Status: Unprotected nongame species.
Global Rank:

G5; populations are widespread, abundant, and secure.

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. 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.