Cloudless Sulphur

Phoebis sennae

cloudless_sulphur_2012.jpg

photo of a Cloudless Sulphur nectaring on a thistle
The cloudless sulphur is the large, clear-yellow butterfly you see flying rapidly to the southeast in late summer and fall.
Donna Brunet
Family

Pieridae (whites, sulphurs, yellows)

Description

The cloudless sulphur is larger than other Missouri sulphurs. The dorsal (top) side is mostly unmarked, although females have a thin black border and two spots near the leading edge of the forewing. The extent of the markings on the lower side varies, with females more heavily marked and some males virtually unmarked.

Larvae are yellowish green with black dots and a yellow line along each side.

Size

Wingspan: 1¾–2¾ inches.

Habitat and conservation

Usually seen in fields, prairies, and gardens. This is the large yellow butterfly that flies rapidly in a southeasterly direction as it migrates in late summer and fall.

Foods

Larvae feed on partridge pea, sennas, and other legumes (plants in the bean family). Adults have a long proboscis (“tongue”); this is one of the few butterflies that can take nectar from flowers with long, tubular corollas such as trumpet vine, petunias, four o’clocks, morning glories, leadwort, and phlox. Because they can feed from so many kinds of flowers, they can select ones with high-quality nectar and are less reliant on food consumed and stored in the larval form.

image of Cloudless Sulphur Distribution Map
Distribution in Missouri

Statewide.

Status

Summer resident, with numbers varying greatly from year to year.

Life cycle

Cloudless sulphurs move into Missouri with the arrival of warm weather and return south in the fall. Although it can’t survive our winters, this species migrates north each year to breed wherever females find suitable food plants. Eggs are laid singly. There are two or more generations in our state.

Human connections

Our word “butterfly” originated with a butter-yellow species like this. In French, the word for “butterfly” is “papillon.” It comes from the Latin word “papilio,” from which our word “pavilion” is derived. The Italian word for butterfly is “farfalle,” which also describes a pasta shape!

Ecosystem connections

The caterpillars are herbivores that graze on vegetation. The adults serve a role in pollination. All stages provide food for predators.