Pontia occidentalis (Reakirt, 1866)
Status: Uncommon resident
NENHP Ranking: S2, Tier 2
Range: This species is a resident from much of Alaska east through Ontario, and south through Colorado, Utah, Nevada and northern California. In Nebraska it has been found in the panhandle and Dundy County.
Broods/Flight Times: Up to three broods from mid-May through August
Larval Hostplant(s): Various members of the Crucifer family are listed, of which the following occur in Nebreaska: Mustards (Arabis drummondi, A. glabra, Brassica nigra, Chorispora tennilla, Sisymbrium altissimum), Flixweed (Descurainia sophia), and varities of Peppergrasses (Lepidium virginicum and L. densiflorum).
Habitat: The Western White is most often encountered on rocky or short grass prairie hillsides, although it has also been found in “urban” areas.
Found at: Buffalo Creek SWMA, Sidney I-80 East rest stop
Overwintering: As pupae
Similar Species: Checkered and California Whites