New Jersey Butterfly Club

Orange Sulphur

Colias eurytheme

Identification: Small—1.9” (Slightly larger than Cabbage White). Almost never seen with wings open. Below: FW and HW bright yellow, with deep orange on the FW usually seen extending just above the HW margin. HW with pink-rimmed silvery spot in center. Some females of this and Clouded Sulphur are very whitish, especially above, and are not separable in the field. Extensive black wing margins above and presence of silvery spot on HW separate these white-form females from (the even whiter) Cabbage White.

NJ Status and Distribution: Resident. Common and widespread throughout.

Habitat: Open, sunny, upland fields and meadows. Easily attracted to gardens with flowers such as Butterfly Bush, Purple Coneflower, asters, and milkweeds.

Flight Period: Overlapping broods resulting in an extended main flight period from March through December. Extreme dates: North Jersey 1/1-12/31; South Jersey 1/1-12/31.

Caterpillar Food Plants: Alfalfa (Medicago sativa), clovers, and many other legumes.

Overwintering Stage: Pupa and caterpillar.

Good Locations: Anywhere and everywhere except forests. Sometimes abundant in Alfalfa fields.

Comments: Not always easy to separate from Clouded Sulphur, especially when faded or when the FW is not visible. The 2 species are known to hydridize, producing some bewildering individuals. And to confuse matters even more, very pale-yellow individuals are frequently seen. So do not be embarrassed to admit that you have seen a sulphur, species unknown.

An underappreciated butterfly, perhaps because it is so common. But seeing a fresh Orange Sulphur on an intense purple New England Aster will convince you otherwise.