Becker's White (Pontia beckerii [W. H. Edwards])
Wing span: 1 5/8 - 2 inches (4 - 5 cm).
Identification: Upperside of both male and female is white, with black spots near tip of forewing. Inside the forewing cell is a square black bar with a curved white center. The underside of the hindwing of both sexes has wide green edging along the veins, confined by a white median band.
Life history: Males patrol ravines in search of females. Females lay eggs singly on host stems, buds, leaves, flowers, and fruits.
Flight: Several flights from March-October.
Caterpillar hosts: Plants of mustard (Brassicaceae) family including mustards (Brassica), and hedge mustard (Sisymbrium) species; and bladder-pod (Isomeris arborea) in the caper family (Capparidaceae).
Adult food: Flower nectar including hedge mustard and alfalfa.
Habitat: Arid brushlands, desert foothills and canyons, fields.
Range: British Columbia and Alberta south to Baja California; east of the Cascades and Sierra Nevada, east and south to western Montana and New Mexico.
Conservation: Not required.
Management needs: None required.
The Nature Conservancy Global Rank: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
Scott, J. A. 1986. The butterflies of North America. Stanford University Press, Stanford, Calif. 583 pages, 64 color plates. Tilden, J. W. 1986. A field guide to western butterflies. Houghton-Mifflin Co., Boston, Mass. 370 pages, 23 color plates.
Author: Jane M. Struttmann
State and Regional References:
Opler, Paul A. 1999. Peterson Field Guide to Western Butterflies, revised edition. Houghton Mifflin Co., Boston, Mass. Stanford, R.E. and P.A. Opler. 1993. Atlas of Western USA Butterflies. Privately published, Denver, Colo.