The Cloudless Sulphur is a stunning yellow butterfly that can easily brighten up any garden or outdoor space. Found throughout most of the mainland United States, it’s most common in the eastern US and southern portions of the western US, sometimes reaching Canada 1. The scientific name for this beautiful creature is Phoebis sennae, which draws inspiration from Phoebe, sister of the sun godApollo in Greek and Roman mythology, and the genus Senna – home to many of the butterfly’s host plants for larvae 2.
These captivating insects go through a fascinating life cycle, starting as eggs and transforming into caterpillars, then pupae, and finally emerging as adult butterflies. Observing Cloudless Sulphurs in your garden can bring a deeper appreciation for the extraordinary natural world. Male Cloudless Sulphurs boast lemon-yellow wings with no markings, while females can exhibit either yellow or white wings with irregular, patchy black borders and dark spots 3.
Cloudless Sulphur: Overview
Physical Characteristics
The Cloudless Sulphur, also known as Phoebis sennae, is a large, vibrant butterfly species. Their wingspan ranges from 2 to 2¾ inches (5.4 – 7.0 cm). There are some distinguishing features between males and females:
- Males: lemon yellow upper surface, no markings
- Females: yellow or white upper surface, irregular patchy black borders, dark spot on upper forewing
The lower surface of the hindwing in both sexes showcases two pink-edged silver spots.
Distribution and Habitat
These butterflies are mostly found in the eastern United States and southern areas of the western United States, with some sightings reported in Canada. In Florida, they are considered one of the most common butterfly species.
The Cloudless Sulphur’s preferred habitat includes:
- Gardens
- Open fields
- Road edges
- Wetlands
- Disturbed areas with host plants
They thrive in these environments by feeding on nectar from various flowers, often found in abundance in their habitat. Their larvae feed on host plants in the genus Senna, for which the species is scientifically named.
Feature | Cloudless Sulphur |
---|---|
Scientific Name | Phoebis sennae |
Habitat | Gardens, open fields, road edges, wetlands, and disturbed areas |
Larval Host Plants | Senna species |
Average Wingspan | 2 to 2¾ inches (5.4 – 7.0 cm) |
Distinguishing Features | Yellow or white upper surface with black borders and silver spots on the hindwings |
Life Cycle and Behavior
Caterpillar Stage
The caterpillar of the cloudless sulphur goes through several stages of growth called instars. During this stage, they feed on host plant leaves1. Their primary food sources include various species of cassia plants, such as partridge pea2. Some notable characteristics of cloudless sulphur caterpillars include:
- Green or yellow coloration
- White or faint yellow lateral stripe
- Interior feeders, living within rolled leaves for protection
Adult Butterfly Stage
The adult cloudless sulphur is an easily recognizable butterfly with its large, clear-yellow coloration. Males are typically solid yellow, while females have a yellow base with a black border on their wings, along with a dark spot at the center of each forewing3. A few key features of adult cloudless sulphurs include:
- Long proboscis, allowing them to access nectar from long-tubed plants4
- Rapid flight, especially during migration
- Active during spring and summer months
The cloudless sulphur has a unique behavior of migrating southward in late summer and fall, which is easily observed in their rapid flight patterns5. As adults, they do not hibernate or undergo diapause6. Their long proboscis enables them to feed on nectar from the same long-tubed plants that serve as a food source for hummingbirds7.
Cloudless Sulphur Caterpillar | Adult Cloudless Sulphur |
---|---|
Feeds on host plant leaves | Feeds on nectar |
Lives within rolled leaves | Active during migration |
Green or yellow color | Clear-yellow color |
Feeding and Nutrition
Nectar Plants
Cloudless Sulphur butterflies primarily feed on nectar from various plants. They have a preference for:
- Cardinal flower: A bright-red flower attracting pollinators with its vibrant color.
- Scarlet sage: A red tubular flower that attracts hummingbirds and butterflies alike.
Host Plants
The caterpillars of the Cloudless Sulphur have specific host plants, mainly in the Senna and Cassia families:
- Senna: A group of plants with yellow flowers that provide essential nutrients for the larvae.
- Cassia: A similar group of plants that also serves as a primary food source for the growing caterpillars.
Nectar Plants | Host Plants |
---|---|
Cardinal flower | Senna |
Scarlet sage | Cassia |
Migration Patterns and Seasonality
The Cloudless Sulphur Butterfly is a large yellow butterfly that can be found across the mainland United States. Let’s explore its migration patterns and seasonality.
These pretty butterflies are known to migrate when the seasons change. They’re most commonly found in the eastern United States and southern portions of the western United States.
They’ve also been spotted as far north as Canada. The migration is driven by temperature changes, especially in the warmer months.
Some key features of the Cloudless Sulphur Butterfly are:
- Large yellow color
- Wingspan of 2 to 2¾ inches (5.4 – 7.0 cm)
- Males have a lemon-yellow upper surface with no markings
- Females may be yellow or white with irregular black borders
- Lower surface of hindwing has 2 pink-edged silver spots
In general, the Cloudless Sulphur Butterfly has fascinating migration and seasonality patterns that vary depending on the region and climate.
Species Relationship and Interactions
The Cloudless Sulphur butterfly is a large yellow butterfly found throughout most of the mainland United States. It plays a significant role in pollination and has specific interactions with certain plants and animals.
One of the primary interactions involves the butterfly’s relationship with its host plants. Caterpillars feed on the leaves of plants from the pea family, such as Cassia and Senna species. Adult butterflies are attracted to bright-colored flowers where they can retrieve nectar. This process aids in pollination as they visit several flowers and facilitate the transfer of pollen.
Cloudless Sulphur butterflies also experience various predator-prey relationships. For example, they become prey for birds, spiders, and other insects. Additionally, they have developed defenses to avoid predation, such as camouflage, warning coloration, and swift flight patterns.
- Host plants: Cassia and Senna species
- Common predators: Birds, spiders, insects
- Defenses: Camouflage, warning coloration, swift flight
In comparison to other butterfly species, the Cloudless Sulphur stands out due to its striking color and relatively larger size. While many butterfly species contribute to pollination, each has unique host plants and methods of survival. Butterflies interact with various species in their ecosystem, and recognizing their ecological significance allows us to understand the importance of preserving these delicate insects.
Feature | Cloudless Sulphur | Other Butterfly Species |
---|---|---|
Size | Larger, wingspan up to 2.75 in | Varies, generally smaller |
Color | Striking bright yellow | Varies widely |
Host Plants | Cassia and Senna species | Unique for each species |
Role in ecosystem | Pollination, predator-prey interactions | Pollination, predator-prey interactions |
Footnotes
- https://fieldguide.mt.gov/speciesDetail.aspx?elcode=IILEPB1010 ↩
- https://entnemdept.ufl.edu/creatures/bfly/bfly2/cloudless_sulphur.htm ↩
- https://www.fs.usda.gov/wildflowers/pollinators/pollinator-of-the-month/cloudless-sulphur-butterfly.shtml ↩
- https://alabama.butterflyatlas.usf.edu/species/details/113/cloudless-sulphur ↩
- https://mdc.mo.gov/discover-nature/field-guide/cloudless-sulphur ↩
- https://fieldguide.mt.gov/speciesDetail.aspx?elcode=IILEPB1010 ↩
- https://alabama.butterflyatlas.usf.edu/species/details/113/cloudless-sulphur ↩
.
17 Comments. Leave new
When you first identified the little guys for me, I googled them and saw all these photos of bright green caterpillars. I was thinking “But my guys are bright yellow – they don’t look the same!”. Thanks for clearing it up for me – I have flower-munchers. And lots of them!! Luckily my cassia is in massive bloom so I don’t mind sharing it with the caterpillars.
hey! where did they go? my cassia was full of them and today i checked and they are gone (as are all the cassia flowers) but no chrysalises! i was expecting to enjoy watching to whole process but they chewed and blew outta dodge. ingrates!
Hi Veek,
Perhaps your caterpillars left in mass to find a good location for pupation. Caterpillars often leave the food plant and seek shelter elsewhere.
Sadly, this chrysalis looks dead.
Really, it still looks viable to us.
How can I attach a photo to my comments?
You should send the photos using the “Ask WTB?” link on the homepage.
my son found one we put it in an open top jar it made its way into a corner and immediately turned into a green and orange cocoon . we’ve had it almost a week and are wondering how long until it hatches.
we’re in ventura California btw….thanks
We found a whole group of the cloudless sulphur caterpillar on our small cassia plant that we bought in Palm Springs a few years ago.
We are wondering what it will look like as a butterfly. I guess we will look up the same name but in a butterfly. Oh, yes are they a harm to our plant because we would hate to have to relocate them. Also, will they cocoon on the Cassia or move to a more private area?
We found a whole group of the cloudless sulphur caterpillar on our small cassia plant that we bought in Palm Springs a few years ago.
We are wondering what it will look like as a butterfly. I guess we will look up the same name but in a butterfly. Oh, yes are they a harm to our plant because we would hate to have to relocate them. Also, will they cocoon on the Cassia or move to a more private area?
The Cloudless Sulphur is a medium size bright yellow butterfly. The chrysalis stage may or may not occur on the plant. Leaves grow back.
Thank you so much for the information and encouragement! Best wishes always, Ellen ?
You are most welcome Ellen. Thank you for keeping our archives populated with the wonderful butterflies in your yard.
Hi! I just found this same caterpillar on my new Cassia tree. Should I leave it alone, or will it strip the tree of the blooms and leaves? ☹️
You would need to have 1000s of caterpillars to strip the trees. A few won’t even be noticed, and you will have some showy yellow butterflies as a result.
I planted a Cassia Popcorn tree a couple of months ago and I already have a Cloudless Sulfur caterpillar eating the yellow flowers (the caterpillar is a beautiful yellow). I have raised Swallowtails and Monarchs in my lanai inside a butterfly net. What can I feed this guy to keep him inside?