Size: 1.25 - 1.75 inches wingspan

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Key ID features:  Above, male white with black or gray markings on forewing, female has more extensive markings on both wings. Below dark overscaling creates gray-green margins along hindwing veins, darker in spring.

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Similar species:  Co-occurs with Checkered White in SE Oregon. The two species are not separable in flight. Female Checkered White is less sharply marked, often with olive or brown shades above instead of the gray-black of Western.  Male Checkered White has narrower gray marks on the forewing margins with more white in between, and forewing markings are less extensive in general.

 

Host plant: Many native species in the mustard family.

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Habitat: Open habitats, including woodland openings, mountain meadows, and barren areas above tree line.

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Range: Throughout Oregon west of the Cascade Crest.

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Season: Mid-March to mid-September

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Abundance: Common

 

Conservation Status: Secure