San Diego Natural History Museum--Your Nature ConnectionSDNHM Field Guide

Phoebis sennae
Cloudless Sulphur

Family: PIERIDAE (Whites and Sulphurs)

The genus name Phoebis comes from the Greek phiobos meaning "pure" or "radiant," and the species name most likely refers to one of the butterfly's host plants, Senna (Cassia sp.).


The male Cloudless Sulphur is a lovely, solid-yellow butterfly with a wingspan of about 2 1/2 - 2 3/4 inches. The female can be yellow or white and has a brownish-black border. Both sexes have two small silver spots on the underside of their hindwings. Larvae are yellow with horizontal brownish stripes.

Range and Habitat

The Cloudless Sulphur ranges throughout Southern California and the Southwest, east through the southern United States and south into Baja California and northern Mexico.

Natural History

Like most sulphurs, this butterfly rarely perches with open wings. Males favor rapid flight and constantly patrol for receptive mates. Females lay eggs singly on the leaves or buds of host plants on which caterpillars later feed. Cloudless Sulphurs hibernate as pupae. Adults fly from April through May in California, though they may have many flights year-round in the southeastern United States.

Related or Similar Species

Sleepy Orange


Jaeger, Edmund C. A Source-Book of Biological Names and Terms. 1955 3rd ed. Springfield, Illinois: Charles C. Thomas, Publisher.

Stewart, Bob. (1998). Common Butterflies of California. Patagonia, Arizona: West Coast Lady Press.

Northern Prairie Wildlife Research Center. Butterflies of North America: Cloudless Sulphur Webpage. Available at

Cloudless Sulfur, photo by Bob Parks

Cloudless Sulphur pupa

Text by Liza Blue in consultation with Christian Manion.
Photos by Bob Parks.

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