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 545 verified sightings
Observation date: Apr 26, 2019
Submitted by: Lennox Saunders
Region: Saskatchewan, Canada
Verified by: alchem30
Verified date: Jun 18, 2019
Observation date: Aug 11, 2017
Submitted by: Anne Belton
Region: Alberta, Canada
Verified by: Norbert Kondla
Verified date: Nov 24, 2018
Observation date: May 22, 2018
Submitted by: Ken Dies
Region: Alberta, Canada
Verified by: Norbert Kondla
Verified date: Nov 24, 2018
Observation date: Sep 07, 2018
Submitted by: Solange
Region: Alberta, Canada
Verified by: Norbert Kondla
Verified date: Nov 24, 2018
Observation date: Aug 06, 2018
Submitted by: Gonodactylus
Region: Nunavut, Canada
Verified by: rosslayberry
Verified date: Oct 16, 2018
Observation date: Aug 23, 2016
Submitted by: hydapse
Region: Park County, Wyoming, United States
Verified by: J_Martineau
Verified date: Oct 11, 2018
Observation date: Jun 26, 2018
Submitted by: Judeen
Region: Ada County, Idaho, United States
Verified by: stevekohler
Verified date: Oct 03, 2018
Observation date: Jul 10, 2015
Submitted by: dlister
Region: Douglas County, Nevada, United States
Verified by: Ken Davenport
Verified date: Aug 19, 2018
Observation date: Jul 21, 2018
Submitted by: dsperanza
Region: Montana, United States
Verified by: J_Martineau
Verified date: Jul 26, 2018
Observation date: Jul 11, 2018
Submitted by: MAKI
Region: Placer County, California, United States
Verified by: Ken Davenport
Verified date: Jul 13, 2018
Observation date: May 22, 2018
Submitted by: hiker96
Region: Yakima County, Washington, United States
Verified by: davidwdroppers
Verified date: May 25, 2018
Observation date: Aug 10, 2017
Submitted by: OhioHick
Region: Glacier County, Montana, United States
Verified by: J_Martineau
Verified date: Jan 16, 2018
Observation date: May 09, 2017
Submitted by: RobertWeeden
Region: Fairbanks North Star, Alaska, United States
Verified by: Norbert Kondla
Verified date: Sep 23, 2017
Observation date: Sep 02, 2017
Submitted by: Paul Prappas
Region: British Columbia, Canada
Verified by: Norbert Kondla
Verified date: Sep 22, 2017
Observation date: Jun 21, 2017
Submitted by: A_baldini
Region: Larimer County, Colorado, United States
Verified by: mikefisher
Verified date: Jul 28, 2017
Observation date: Jul 22, 2016
Submitted by: Bixia
Region: Alpine County, California, United States
Verified by: Ken Davenport
Verified date: Jul 13, 2017
Observation date: Aug 13, 2016
Submitted by: jim8435wisc
Region: Fairbanks North Star, Alaska, United States
Verified by: Norbert Kondla
Verified date: Apr 29, 2017
Observation date: Jun 25, 2016
Submitted by: hiker96
Region: Box Elder County, Utah, United States
Verified by: RaisingButterfl...
Verified date: Apr 22, 2017
Observation date: Jun 11, 2016
Submitted by: J_Martineau
Region: Sheridan County, Wyoming, United States
Verified by: J_Martineau
Verified date: Jan 09, 2017
Observation date: Aug 29, 2016
Submitted by: edwardbirding
Region: Harney County, Oregon, United States
Verified by: Ken Davenport
Verified date: Sep 15, 2016
Observation date: Aug 04, 2016
Submitted by: Sue Orlowski
Region: Whitman County, Washington, United States
Verified by: davidwdroppers
Verified date: Aug 24, 2016
Observation date: Jun 13, 2016
Submitted by: BCBirdman
Region: British Columbia, Canada
Verified by: Norbert Kondla
Verified date: Jul 19, 2016
Observation date: Jun 30, 2016
Submitted by: Kristie Nelson
Region: Mono County, California, United States
Verified by: Ken Davenport
Verified date: Jul 04, 2016
Observation date: Jun 05, 2016
Submitted by: PDunwiddie
Region: Pierce County, Washington, United States
Verified by: davidwdroppers
Verified date: Jun 06, 2016
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