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.
Wingspan: 1¾–2¾ inches.
Habitat and Conservation
Usually seen in fields, prairies, and gardens. This is the large yellow butterfly that flies rapidly southward as it migrates in late summer and fall.
Larvae feed on partridge pea (Chamaecrista fasciculata), wild senna (Senna marilandica), 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.
Summer resident, with numbers varying greatly from year to year.
Cloudless sulphurs survive winters in the southeastern United States. In spring, they move north into Missouri with the arrival of warm weather. As they move northward, they breed and lay eggs, increasing their populations. Over the course of the summer, they can expand their range into Canada. Then, in late summer and fall, adult butterflies fly south.
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.
You can improve habitat for cloudless sulphurs by planting their caterpillar food plants (partridge pea and wild senna) and by cultivating a variety of native wildflowers that provide nectar for these beautiful insects.
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!
The caterpillars are herbivores that graze on vegetation. The adults serve a role in pollination. All stages provide food for predators.
The caterpillars of cloudless sulphurs are beautifully camouflaged as they feed on partridge pea and wild senna. Their yellow-green coloration, with diffuse darker banding, makes them resemble one of the long seedpods that are often abundant on their food plants.