Western White
Pontia occidentalis (Reakirt, 1866)
Family: Pieridae
Subfamily: Pierinae
Identification: Upperside of forewing has marginal markings that are lighter than the submarginal stripe. Below, forewing tip and hindwing have veins outlined with gray-green. Short-day spring and fall forms have more prominent markings.
Wing Span: 1 1/2 - 2 1/8 inches (3.8 - 5.3 cm).
Life History: Males patrol hilltops and ridges for receptive females. Females lay eggs singly on host plants. Caterpillars will feed on leaves but prefer buds, flowers, and fruits. Chrysalids hibernate.
Flight: One flight from June-July in far north; two flights from May-August in the south.
Caterpillar Hosts: Flowers and fruits of various members of the mustard (Brassicaceae) family.
Adult Food: Flower nectar.
Habitat: Mountain peaks, slopes, hilltops, railroad yards, open plains, roadsides.
Range: Alaska south to central California, northern Arizona and northern New Mexico; east to North Dakota and central Ontario.
Conservation: Not usually required.
NCGR: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
Management Needs: None noted.
Comments: NULL
Verified Sightings
Displaying 1 - 24 of 605 verified sightings
Observation date: Jun 24, 2022
Submitted by: yasobara
Region: Kittitas County, Washington, United States
Verified by: davidwdroppers
Verified date: Feb 03, 2023
Observation date: Jun 21, 2019
Submitted by: nonololo
Region: Canada
Verified by: Paul Prappas
Verified date: Jan 31, 2023
Observation date: Aug 13, 2022
Submitted by: Northern John
Region: Manitoba, Canada
Verified by: chalicerae
Verified date: Nov 30, 2022
Observation date: Aug 24, 2022
Submitted by: bshettler
Region: Manitoba, Canada
Verified by: chalicerae
Verified date: Nov 30, 2022
Observation date: Sep 07, 2022
Submitted by: Cascade Colors
Region: Larimer County, Colorado, United States
Verified by: mikefisher
Verified date: Oct 15, 2022
Observation date: Jul 14, 2022
Submitted by: Paul Prappas
Region: Box Elder County, Utah, United States
Verified by: Paul Prappas
Verified date: Sep 19, 2022
Observation date: Sep 11, 2022
Submitted by: dlister
Region: Walworth County, South Dakota, United States
Verified by: J_Martineau
Verified date: Sep 19, 2022
Observation date: Jun 24, 2019
Submitted by: Liz Osborn
Region: British Columbia, Canada
Verified by: Paul Prappas
Verified date: Sep 16, 2022
Observation date: Jun 24, 2019
Submitted by: Liz Osborn
Region: British Columbia, Canada
Verified by: Paul Prappas
Verified date: Sep 14, 2022
Observation date: Aug 06, 2019
Submitted by: Liz Osborn
Region: British Columbia, Canada
Verified by: Paul Prappas
Verified date: Sep 13, 2022
Observation date: Jul 31, 2019
Submitted by: Liz Osborn
Region: British Columbia, Canada
Verified by: Paul Prappas
Verified date: Sep 13, 2022
Observation date: Aug 17, 2019
Submitted by: Aat
Region: British Columbia, Canada
Verified by: Paul Prappas
Verified date: Sep 13, 2022
Observation date: Oct 17, 2019
Submitted by: Claire Christensen
Region: British Columbia, Canada
Verified by: Paul Prappas
Verified date: Sep 13, 2022
Observation date: Oct 17, 2019
Submitted by: Claire Christensen
Region: British Columbia, Canada
Verified by: Paul Prappas
Verified date: Sep 13, 2022
Observation date: Aug 20, 2022
Submitted by: MAKI
Region: Elko County, Nevada, United States
Verified by: Ken Davenport
Verified date: Aug 26, 2022
Observation date: Aug 23, 2021
Submitted by: WYbutterflyer1
Region: Albany County, Wyoming, United States
Verified by: J_Martineau
Verified date: Aug 26, 2022
Observation date: Aug 11, 2022
Submitted by: hiker96
Region: Pierce County, Washington, United States
Verified by: davidwdroppers
Verified date: Aug 14, 2022
Observation date: Jun 27, 2022
Submitted by: glennfine
Region: Siskiyou County, California, United States
Verified by: Ken Davenport
Verified date: Jul 26, 2022
Observation date: Jun 22, 2022
Submitted by: MAKI
Region: Lassen County, California, United States
Verified by: Ken Davenport
Verified date: Jul 04, 2022
Observation date: Jul 25, 2021
Submitted by: jeh802
Region: Saskatchewan, Canada
Verified by: alchem30
Verified date: Jun 15, 2022
Observation date: May 06, 2022
Submitted by: HimmelBerries
Region: Saskatchewan, Canada
Verified by: alchem30
Verified date: Jun 15, 2022
Observation date: May 05, 2022
Submitted by: heinert
Region: Stark County, North Dakota, United States
Verified by: stevekohler
Verified date: May 31, 2022
Observation date: May 05, 2022
Submitted by: jrmbutterfly
Region: Alberta, Canada
Verified by: davidwdroppers
Verified date: May 06, 2022
Observation date: Apr 07, 2022
Submitted by: Luna-Linuche.76
Region: Klamath County, Oregon, United States
Verified by: Ken Davenport
Verified date: Apr 09, 2022
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