Colias philodice

Colias philodice
	Male specimen
Conservation status
	; Secure (NatureServe)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Family:	Pieridae
Genus:	Colias
Species:	C. philodice
Binomial name
	Colias philodice; Godart, 1819

Colias philodice, the common sulphur or clouded sulphur, is a North American butterfly in the family Pieridae, subfamily Coliadinae.

Description

This species is a typical member of the genus. Both genders typically have pale yellow wings above with no traces of orange, unlike its close cousin the

orange sulphur

which may also be yellowish. Males have clean borders, while females have yellow dots within this region. Females sometimes exhibit a white form known as alba.

The underside of the male's wings is yellow while the female's is yellow or greenish white, and both have a doubled

hindwing spot trimmed in brownish red. The hindwings show a series of four small red spots along the outer third portion, a trait that distinguishes the other North America species such as Colias interior, with exception of the orange sulphur which also shows them. Its wingspan is 32 to 54 mm.^[2]

Form alba

This species has white form alba which can be very common in some populations, while rare in others. It can be confused with other white forms of Colias particularly that of Colias eurytheme. It can often be distinguished by the border pattern of both wings, though some individuals are impossible to separate without the presence of other "normal" specimens. Though they differ in flight style, the white forms of Colias may be confused with other pierids such as Pieris rapae and Pontia protodice.^[3]

White form males are also known, but they are exceedingly rare in this species.^[4]

Habitat

This butterfly may be encountered in fields, lawns, alfalfa or clover fields, meadows, and roadsides. Swarms of these butterflies will congregate at mud puddles. They range over most of North America with the exception of Labrador, Nunavut, and northern Quebec.^[2] They migrate every year.^[5]

Nectar plants

Clouded sulphurs

Trifolium species), and tall verbena (Verbena bonariensis

) and many more.

Host plants

Ground-plum (

Medicago sativa), white sweet clover (Melilotus albus), self-heal (Prunella vulgaris), black locust (Robinia pseudoacacia), white clover (Trifolium repens), red clover (Trifolium pratense), vetch (Vicia

species).