Butterflies and Moths of North America

collecting and sharing data about Lepidoptera

  Sighting 1421190

Western White
Pontia occidentalis

Observation date: April 05, 2026
Submitted by: Cascade Colors
Specimen type: Photograph
Observation notes: I don't think I've seen a white (other than Cabbage) this early in this county, so not sure. It was very far away, so photo isn't super detailed.
Status: Resident
Verified by: mikefisher
Verified date: April 12, 2026
Coordinator notes: Yes Lynn...your suggested ID is correct. This is the early/spring flying form of the Western White with the bold green venation on the underside of the hindwings (form calyce). This form is found above timberline in the summer as the single flight there vs. successive flights that can be produced in the warmer summertime at lower altitude...larger individuals with reduced/less prominent venation below (but usually always retains some of the greenish color). The well defined black border marking on the forewings separates it from the Checkered White (although some females can be quite confusing!). Mike
Checklist region(s): United States, Colorado, Grand County