Attributes of Colias occidentalis

Western Sulphur
Colias occidentalis Scudder, 1862

Family: Pieridae
Subfamily: Coliadinae
Identification: Upperside of male bright yellow with wide black border; orange morph is orange with yellow at costa and wing bases. Female pale yellow to greenish white with border blurry, incomplete, or absent; orange morph dull orange with wide black borders and dark veins. Underside of both sexes with pink wing fringes and golden yellow hindwing; orange morph green-gray to orange; both with dark overscales.
Wing Span: 1 3/4 - 2 1/2 inches (4.5 - 6.3 cm).
Life History: Males patrol in valleys or open areas near host plants for females. Females lay eggs singly on host plant leaves. Late-stage caterpillars hibernate.
Flight: May-August, mainly June-July.
Caterpillar Hosts: Plants of the pea family (Fabaceae) including vetch (Vicia angustifolia), sweet vetch (Hedysarum), lupines (Lupinus), and white sweet clover (Melilotus alba).
Adult Food: Flower nectar.
Habitat: Open areas including meadows, sagebrush flats, conifer forest openings, power-line cuts.
Range: Extreme southern British Columbia and northwestern United States south to north coastal California and central Utah.
Conservation: Some populations affected by grazing and fire suppression.
NCGR: G3, G4 - Very rare or local throughout its range or found locally in a restricted range OR Apparently secure globally, though it might be quite rare in parts of its range, especially at the periphery. Subspecies chrysomelas is T2,T3 and is threatened by fire suppression, improper logging, and invasive alien weeds.
Management Needs: Not reported.
Taxonomy Notes:

Images of Colias occidentalis

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Colias occidentalis - colias_occidentalis_kondla2.jpg

Colias occidentalis - colias_occidentalis_kondla2.jpg
Colias occidentalis - colias_occidentalis_kondla1.jpg

Colias occidentalis - colias_occidentalis_kondla1.jpg

The map below displays all BAMONA data for this species and has three different data layers:
1. All records (yellow dots)   2. Recently verified records (orange dots)*   3. US county records (purple)

There are also three base layers: 1. Satellite    2. Normal   3. Hybrid

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*The orange dots on the map provide access to information about the 400 most recently verified sightings of this species. Sometimes, there are several records at the same location. Use the table view to access these records.

By default, the fifty most recently verified sightings are below. Sort by Observation Date to see the most recent sightings, or filter the sightings by region to get a regional list.

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Observation Date Submitter Region Verified Datesort icon
January 01, 1950 legacy.reporter Siskiyou County, California, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Humboldt County, California, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Trinity County, California, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Shasta County, California, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Mendocino County, California, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Glenn County, California, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Tehama County, California, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Lake County, California, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Glenn County, California, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Colusa County, California, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Sonoma County, California, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Napa County, California, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Solano County, California, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Del Norte County, California, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Boundary County, Idaho, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Bonner County, Idaho, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Kootenai County, Idaho, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Shoshone County, Idaho, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Latah County, Idaho, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Clearwater County, Idaho, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Nez Perce County, Idaho, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Idaho County, Idaho, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Adams County, Idaho, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Boise County, Idaho, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Elmore County, Idaho, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Lemhi County, Idaho, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Owyhee County, Idaho, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Franklin County, Idaho, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Lincoln County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Flathead County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Glacier County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Sanders County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Lake County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Mineral County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Missoula County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Ravalli County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Granite County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Powell County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Lewis And Clark County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Cascade County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Broadwater County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Deer Lodge County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Silver Bow County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Beaverhead County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Jefferson County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Judith Basin County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Golden Valley County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Stillwater County, Montana, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Yamhill County, Oregon, United States December 31, 2004 Details
January 01, 1950 legacy.reporter Marion County, Oregon, United States December 31, 2004 Details