Western Sulphur
Common NameWestern Sulphur
Scientific NameColias alexandra
FamilyPieridae
SubfamilyColiadinae
Wingspan (mm)50
Wing Patternsolid
Primary Colorsyellow, reddish-pink
HabitatOpen woodlands, meadows, subalpine areas, mountain valleys
Geographic RangeWestern North America, from British Columbia and Alberta south through the Rocky Mountains to Arizona and New Mexico
Host PlantsAstragalus, Thermopsis
Flight PeriodJune to August
Conservation Statusleast-concern
Lifecycle NotesEggs are laid singly on host plant leaves. Larvae are green with a white stripe, feeding on legumes and overwintering as larvae. Pupation occurs in a green chrysalis.
Identification TipsLook for the bright yellow wings with a reddish-pink fringe. The key feature is the single, often silver-centered, dark-ringed spot on the hindwing underside.
Description
A medium-sized, bright yellow butterfly with a distinctive reddish-pink fringe along the wing margins. The underside of the hindwing features a prominent, often dark-ringed, silver or white spot.
