Becker's White (Pontia beckerii) (W.H. Edwards, 1871)

Diagnosis: This white is distinguished by the broad green borders to the veins on the underside of the hindwings, except for the portion of the veins just beyond the cell (two-thirds from the wing base). It leaves the impression of a green surface with a white band crossing it. There is a square black spot in the cell on the forewing upperside. Wingspan: 33 to 48 mm.

Subspecies: Tilden and Smith (1986) list the subspecies pseudochloridice as the one occurring in Canada, but we consider all North American populations to be a single subspecies.

Range: This is a species of dry intermontane valleys in western North America as far south as Baja California. It is found in southern British Columbia mainly in the dry interior valleys.

Specimen collection data

Similar Species: The Spring White (P. sisymbrii), the Checkered White (P. protodice), and the Western White (P. occidentalis) are all similar, but do not have the white band on the hindwing below. The green shading on the veins in these species is more continuous. [compare images]

Early Stages: The larva is green, with narrow orange bands and raised black spots. It usually eats flower buds and flowers of the foodplants, mainly in the mustard family (Brassicaceae).

Abundance: It is uncommon in most areas, but is considered fairly common in the southern Okanagan Valley.

Flight Season: Becker's White has two distinct broods in the northern part of its range, May to June and again in August and September.

Habits: This butterfly is associated with sagebrush and dry canyons and hillsides in British Columbia. The males usually patrol the canyons looking for females.

Remarks: The ultraviolet reflection from the underside of beckerii is particularly strong and may be used by males to find potential mates (Scott, 1986).

© 2002. This material is reproduced with permission from The Butterflies of Canada by Ross A. Layberry, Peter W. Hall, and J. Donald Lafontaine. University of Toronto Press; 1998. Specimen photos courtesy of John T. Fowler.