Clouded Sulphur vs Cloudless Sulphur: A Guide to Identifying Butterfly Species

Clouded sulphur and cloudless sulphur butterflies are two fascinating species often observed in gardens and natural habitats. Both butterfly species have distinct characteristics and appearances, which may leave nature enthusiasts curious about their differences.

The clouded sulphur butterfly, also known as the common sulphur, features yellow wings with a black border in males, while females have a duller hue with yellow spots on the black border. All adults have one black spot on each forewing and faint orange spots on the hindwings source.

On the other hand, the cloudless sulphur butterfly is a large yellow butterfly that does not have the distinct black border seen on clouded sulphurs. These butterflies can access nectar in tubular flowers that other butterflies can’t, with a preference for red flowers such as red morning-glory and scarlet sage source.

Identifying Clouded Sulphur and Cloudless Sulphur

Physical Characteristics

Clouded Sulphur:

  • Males: bright yellow color
  • Females: duller yellow, sometimes white
  • Wing spans: 1.5 to 2 inches

Cloudless Sulphur:

  • Males and females: bright yellow
  • Larger size compared to Clouded Sulphur
  • Wing span: 2.25 to 3.25 inches

Wing Markings

Clouded Sulphur:

  • Single dark spot on each forewing
  • Faint orange spots on hindwings

Cloudless Sulphur:

  • No dark spots on wings

Color Variations

Clouded Sulphur (also known as Orange Sulphur):

  • Male: lemon yellow with black border on wings
  • Female: more white, black border with yellow spots
  • Albino females: common, nearly white

Cloudless Sulphur:

  • Consistent yellow throughout both genders

Comparison table:

Feature Clouded Sulphur (Orange Sulphur) Cloudless Sulphur
Males Bright yellow with black wing borders Bright yellow, larger size, no dark spots on wings
Females Duller yellow, sometimes white Bright yellow, no dark spots on wings
Wing Span 1.5 to 2 inches 2.25 to 3.25 inches
Forewing Dark Spot Present Absent
Hindwing Markings Faint orange spots None

With the help of these characteristics and the comparison table, identifying Clouded Sulphur and Cloudless Sulphur butterflies becomes easier.

Habitats and Distribution

Geographical Range

Cloudless Sulphur:

  • Found throughout most of the mainland United States
  • Primarily in eastern and southern portions of the western United States 1

Clouded Sulphur:

  • Widespread across North America
  • Most common in disturbed open areas 2

Habitat Preferences

Cloudless Sulphur:

  • Prefers red flowers, e.g., red morning-glory, scarlet creeper, cypressvine, and scarlet sage 3
  • Often seen in gardens and open areas 1
  • Larval host plants belong to the genus Senna4

Clouded Sulphur:

  • Favors disturbed open areas, such as meadows and fields 2
  • Usually found near its larval host plants, e.g., plants in the mustard and legume families 2

Comparison Table:

Cloudless Sulphur Clouded Sulphur
Geographical Mainland US, eastern and southern parts Widespread across North America
Range of the western US
Habitat Gardens, open areas, red flowers Disturbed open areas, meadows, fields
Larval Host Genus Senna Mustard and legume families
Plants
Family Pieridae Pieridae

Life Cycle and Host Plants

Eggs

The life cycle of both the clouded and cloudless sulphur butterflies begins with egg-laying on host plants. Female butterflies typically lay eggs singly on the leaves or buds of their preferred host plants:

  • Clouded Sulphur: Mostly partridge pea and alfalfa
  • Cloudless Sulphur: Primarily plants in the Senna genus

Eggs are small, with clouded sulphur eggs appearing as greenish-white and cloudless sulphur eggs as pale yellow.

Caterpillars

After hatching, the caterpillars of both species feed on their host plants. Caterpillars have different appearances:

  • Clouded Sulphur: Green with yellow and black markings, length up to 2.5 cm
  • Cloudless Sulphur: Bright green to yellowish-green with blue-black bands, length up to 4 cm

Caterpillars of both species have few natural predators due to the toxins they accumulate from their host plants, but they may still fall prey to birds, parasitic wasps, or spiders.

Chrysalis and Pupae

Once the caterpillars have reached their final instar, they form a chrysalis or pupa. While in this stage, they undergo metamorphosis to develop into adult butterflies:

  • Clouded Sulphur: Green or brown chrysalis, often blending in with surrounding foliage
  • Cloudless Sulphur: Pale green to brown chrysalis, usually attached to Senna plants

The chrysalis stage lasts for approximately 10 days to 2 weeks.

Adult Butterflies

Adult butterflies of both species are primarily active from spring through fall, with a peak in their populations during fall migration. They can be distinguished by color and size:

  • Clouded Sulphur (Coliadinae): Wingspan of 3.2 cm, pale yellow to white (female) or golden-yellow with black borders (male)
  • Cloudless Sulphur (Phoebis sennae): Wingspan of 6 cm, bright yellow (male) or pale yellow/white (female)

Adult butterflies feed on nectar from tubular flowers, such as those from orange, senna, and other host plants.

Footnotes

  1. Cloudless Sulphur Butterfly – US Forest Service 2

  2. Clouded Sulphur Common Sulphur | MDC Teacher Portal 2 3

  3. Cloudless Sulphur Butterfly – Gardening Solutions – University of …

  4. cloudless sulphur – Phoebis sennae (Linnaeus)

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Australian Caper Gull

 

Australian Caper Gull
Mon, Nov 3, 2008 at 1:17 AM
Hi guys,
Had my first photo opportunity with this Australian Caper Gull (Cepora perimale scyllara ) when it got interested in the Basil in my garden. There are a few of them around but they are usually very flighty and hard to get close to. Hope you like it.
aussietrev
Queensland, Australia

Australian Caper Gull
Australian Caper Gull

Hi Trevor,
Once again, thanks for contributing a new species to our expanding selection of Bugs Down Under.  We are linking to a James Cook University website with additional information on the Australian Caper Gull, a butterfly in the family Pieridae that includes Whites and Sulfurs.

Letter 2 – Chocolate Albatross from Asia

 

Location:  Laos
March 1, 2012
Another of Carol’s butterflies is a member of the family Pieridae, the Whites and Sulfurs, and we quickly identified it on Sambui Butterflies as a Chocolate Albatross,
Appias lyncida vasava.  This individual is also mud puddling.  Sambui Butterflies lists the range as:  “Sri Lanka, India and Burma through the Malay Peninsular. Other subspecies throughout the Oriental Region)” and we are still waiting for information from Carol on the location of this sighting.  According to the Butterflies of Malaysia website:  “Males congregate, sometimes in groups of 50 or more, to imbibe mineralised moisture from damp patches of ground in full sunlight. They are strongly attracted to urine soaked soil, and to mineral-rich sand on recently exposed river beaches in heavily forested areas. If disturbed they fly up in a swirling mass, but resettle to resume feeding at the same spot within a few minutes. Females are normally only seen when flying in search of egg-laying sites within the forest.”

Chocolate Albatross

Hi Daniel,
Thanks for identifying the butterfly!
The River Ou in Laos was where the riverside photos were taken.  We were between Muang La and Luang Prabang.
The caterpillar suspended across a very large open space was probably on a low mountain near a temple near Muang La, Laos.
The other photos were near the Queen’s Garden in a mountainous area near Chiang Rai or Chiang Saen in Thailand.
Where is the butterfly site you are hosting?
Carol

Letter 3 – Dwarf Yellow Sulphur

 

Subject: Dwarf Yellow Sulphur Butterfly
Location: 36 degrees 24’ 57.11”N; 88 degrees 12’ 21.94” W [Tennessee]
September 19, 2012 8:23 pm
I think my previous attempt to send to you did not work. If it did, guess you can delete one of the messages. I believe that the two pictures here are Dwarf Yellow Sulphur Butterflies. They are really small – probably less than an inch from body to wingtip. There were at least a dozen or more in our field late this afternoon (Sept. 19, 2012). We are in Buchanan, TN which is in the northeastern corner of west TN (Kentucky Lake is our county’s eastern border and Kentucky is our northern border). The butterflies did not seem to be looking for flowers – the two here were on blades of grass and some even lit on piles of dead grass left from haying last month. I did not see this butterfly on your site nor on Bug Guide, but based my ID on National Audubon Society Field Guide to Butterflies.
Signature: Mary Ann

Dainty Sulphur

Hi Mary Ann,
We could not find any evidence that you sent this submission twice.  We are thrilled to get your lovely photos of a Dwarf Yellow Sulphur,
Nathalis iole, which BugGuide calls the Dainty Yellow and elaborates:  “Resident in Guatemala north to peninsular Florida and the Southwest. Cannot survive cold winters, therefore every summer re-colonizes through the Great Plains to southeast Washington, southeast Idaho, Wyoming, and Minnesota.”  The habitat is listed as:  “Open, dry places including coastal flats, weedy fields, grasslands, road edges, meadows, and hillsides” where it feeds on “Dogweed, marigold and other asters.”  Known as North America’s smallest Sulphur, this is a new species for our website.

Dainty Sulphur

Letter 4 – Female Orange Sulphur

 

Yellow butterfly
October 12, 2009
Found in the tall bluestem prairie, October 5, 2009
Tom Fuller
Goose Lake Prairie, Illinois

Orange Sulphur
Orange Sulphur

Hi Tom,
This is a female Orange Sulphur, Colias eurytheme.  The female can be distinguished by the spots in the black wing borders.  The caterpillars feed on clover, alfalfa and other legumes.  You can search BugGuide for more information on the species.

Letter 5 – Female Sulphur Butterfly

 

Subject: Beautiful butterfly or moth?
Location: Bellevue NE
September 8, 2012 7:01 am
This was taken in my son’s garden. It’s an 18’x13’ heart shape dedicated to his heart donor.
We live in Bellevue, Nebraska (Omaha) just one mile from the Missouri River.
Never seen it again.
Signature: Eric Zeitner

Female Orange Sulphur

Dear Eric,
What a marvelous idea for a garden dedication.  Congratulations on your son receiving a donor heart.  This lovely butterfly is a female Sulphur, most likely an Orange Sulphur,
Colias eurytheme, also known as the Alfalfa Sulphur.  Because or the light shining through the wings, the distinctive orange color is visible which is a clue to the species, and the lighter spots in the black wing borders indicates that she is a female.  You can read more about the Orange Sulphur on BugGuide.

Letter 6 – Leventine Marbled White from Israel

 

Butterfly from Israel
April 12, 2010
Hi WTB!
Me again from Israel, and still in love with your website!
On my latest hiking trip, this time to Eastern Samaria (north-east of Jerusalem, Israel) on April 9-10, 2010, I saw and photographed loads of bugs. Everything is waking up after the winter, the hills are green and alive!
My first bug is this Melanargia titea titania, who was patiently waiting for me to get my camera out.
Ben
Eastern Samaria, Israel

Leventine Marbled White

Hi Ben,
You sent us enough submissions for three days worth of postings, and that is if we don’t post anything else.  We may have to cherrypick your best and most interesting images to post to What’s That Bug? so that we don’t ignore our other readers.  We found Melanargia titea listed as a Leventine Marbled White on the BioLib website.

Leventine Marbled White

Letter 7 – Mating Sulphur Butterflies

 

Mating Colias Butterflies and a not-so-Common Wood Nymph
Hi Bugman,
Thanks for your great site! You’ve helped me identify lots of critters through your pictures and links from my yard here in Western PA, east of Pittsburgh. I sent you two pictures of mating Colias Butterflies and one picture of a very elusive guest that had me stumped both by its appearance and behavior. The Common Wood Nymph would not let me get near enough to take a good picture. As I approached it would flit away and hide on the underside of a downspout out of range. As I moved away, it would return to the flowers. It did this five or six times, finally flitting to a large white pine and hiding itself thoroughly on the underside of a branch. I could see the eye spots, but there was no way that I had the equipment to take the photo. If I left and took my eyes off the thing, I’d never find it again. I have lived in this area most of my life and have never seen this distinctive butterfly. How common are they really? Or are they just “common” elsewhere than here? Thanks for all your help!
MPK

Hi MPK,
We believe your mating Sulphur Butterflies are Clouded Sulphurs, Colias philodice, but it is possible they are another species in the genus. Wood Nymphs, like many butterflies, may be very numerous in one area, and a mile away they may never be seen. Insects often have very localized populations.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Australian Caper Gull

 

Australian Caper Gull
Mon, Nov 3, 2008 at 1:17 AM
Hi guys,
Had my first photo opportunity with this Australian Caper Gull (Cepora perimale scyllara ) when it got interested in the Basil in my garden. There are a few of them around but they are usually very flighty and hard to get close to. Hope you like it.
aussietrev
Queensland, Australia

Australian Caper Gull
Australian Caper Gull

Hi Trevor,
Once again, thanks for contributing a new species to our expanding selection of Bugs Down Under.  We are linking to a James Cook University website with additional information on the Australian Caper Gull, a butterfly in the family Pieridae that includes Whites and Sulfurs.

Letter 2 – Chocolate Albatross from Asia

 

Location:  Laos
March 1, 2012
Another of Carol’s butterflies is a member of the family Pieridae, the Whites and Sulfurs, and we quickly identified it on Sambui Butterflies as a Chocolate Albatross,
Appias lyncida vasava.  This individual is also mud puddling.  Sambui Butterflies lists the range as:  “Sri Lanka, India and Burma through the Malay Peninsular. Other subspecies throughout the Oriental Region)” and we are still waiting for information from Carol on the location of this sighting.  According to the Butterflies of Malaysia website:  “Males congregate, sometimes in groups of 50 or more, to imbibe mineralised moisture from damp patches of ground in full sunlight. They are strongly attracted to urine soaked soil, and to mineral-rich sand on recently exposed river beaches in heavily forested areas. If disturbed they fly up in a swirling mass, but resettle to resume feeding at the same spot within a few minutes. Females are normally only seen when flying in search of egg-laying sites within the forest.”

Chocolate Albatross

Hi Daniel,
Thanks for identifying the butterfly!
The River Ou in Laos was where the riverside photos were taken.  We were between Muang La and Luang Prabang.
The caterpillar suspended across a very large open space was probably on a low mountain near a temple near Muang La, Laos.
The other photos were near the Queen’s Garden in a mountainous area near Chiang Rai or Chiang Saen in Thailand.
Where is the butterfly site you are hosting?
Carol

Letter 3 – Dwarf Yellow Sulphur

 

Subject: Dwarf Yellow Sulphur Butterfly
Location: 36 degrees 24’ 57.11”N; 88 degrees 12’ 21.94” W [Tennessee]
September 19, 2012 8:23 pm
I think my previous attempt to send to you did not work. If it did, guess you can delete one of the messages. I believe that the two pictures here are Dwarf Yellow Sulphur Butterflies. They are really small – probably less than an inch from body to wingtip. There were at least a dozen or more in our field late this afternoon (Sept. 19, 2012). We are in Buchanan, TN which is in the northeastern corner of west TN (Kentucky Lake is our county’s eastern border and Kentucky is our northern border). The butterflies did not seem to be looking for flowers – the two here were on blades of grass and some even lit on piles of dead grass left from haying last month. I did not see this butterfly on your site nor on Bug Guide, but based my ID on National Audubon Society Field Guide to Butterflies.
Signature: Mary Ann

Dainty Sulphur

Hi Mary Ann,
We could not find any evidence that you sent this submission twice.  We are thrilled to get your lovely photos of a Dwarf Yellow Sulphur,
Nathalis iole, which BugGuide calls the Dainty Yellow and elaborates:  “Resident in Guatemala north to peninsular Florida and the Southwest. Cannot survive cold winters, therefore every summer re-colonizes through the Great Plains to southeast Washington, southeast Idaho, Wyoming, and Minnesota.”  The habitat is listed as:  “Open, dry places including coastal flats, weedy fields, grasslands, road edges, meadows, and hillsides” where it feeds on “Dogweed, marigold and other asters.”  Known as North America’s smallest Sulphur, this is a new species for our website.

Dainty Sulphur

Letter 4 – Female Orange Sulphur

 

Yellow butterfly
October 12, 2009
Found in the tall bluestem prairie, October 5, 2009
Tom Fuller
Goose Lake Prairie, Illinois

Orange Sulphur
Orange Sulphur

Hi Tom,
This is a female Orange Sulphur, Colias eurytheme.  The female can be distinguished by the spots in the black wing borders.  The caterpillars feed on clover, alfalfa and other legumes.  You can search BugGuide for more information on the species.

Letter 5 – Female Sulphur Butterfly

 

Subject: Beautiful butterfly or moth?
Location: Bellevue NE
September 8, 2012 7:01 am
This was taken in my son’s garden. It’s an 18’x13’ heart shape dedicated to his heart donor.
We live in Bellevue, Nebraska (Omaha) just one mile from the Missouri River.
Never seen it again.
Signature: Eric Zeitner

Female Orange Sulphur

Dear Eric,
What a marvelous idea for a garden dedication.  Congratulations on your son receiving a donor heart.  This lovely butterfly is a female Sulphur, most likely an Orange Sulphur,
Colias eurytheme, also known as the Alfalfa Sulphur.  Because or the light shining through the wings, the distinctive orange color is visible which is a clue to the species, and the lighter spots in the black wing borders indicates that she is a female.  You can read more about the Orange Sulphur on BugGuide.

Letter 6 – Leventine Marbled White from Israel

 

Butterfly from Israel
April 12, 2010
Hi WTB!
Me again from Israel, and still in love with your website!
On my latest hiking trip, this time to Eastern Samaria (north-east of Jerusalem, Israel) on April 9-10, 2010, I saw and photographed loads of bugs. Everything is waking up after the winter, the hills are green and alive!
My first bug is this Melanargia titea titania, who was patiently waiting for me to get my camera out.
Ben
Eastern Samaria, Israel

Leventine Marbled White

Hi Ben,
You sent us enough submissions for three days worth of postings, and that is if we don’t post anything else.  We may have to cherrypick your best and most interesting images to post to What’s That Bug? so that we don’t ignore our other readers.  We found Melanargia titea listed as a Leventine Marbled White on the BioLib website.

Leventine Marbled White

Letter 7 – Mating Sulphur Butterflies

 

Mating Colias Butterflies and a not-so-Common Wood Nymph
Hi Bugman,
Thanks for your great site! You’ve helped me identify lots of critters through your pictures and links from my yard here in Western PA, east of Pittsburgh. I sent you two pictures of mating Colias Butterflies and one picture of a very elusive guest that had me stumped both by its appearance and behavior. The Common Wood Nymph would not let me get near enough to take a good picture. As I approached it would flit away and hide on the underside of a downspout out of range. As I moved away, it would return to the flowers. It did this five or six times, finally flitting to a large white pine and hiding itself thoroughly on the underside of a branch. I could see the eye spots, but there was no way that I had the equipment to take the photo. If I left and took my eyes off the thing, I’d never find it again. I have lived in this area most of my life and have never seen this distinctive butterfly. How common are they really? Or are they just “common” elsewhere than here? Thanks for all your help!
MPK

Hi MPK,
We believe your mating Sulphur Butterflies are Clouded Sulphurs, Colias philodice, but it is possible they are another species in the genus. Wood Nymphs, like many butterflies, may be very numerous in one area, and a mile away they may never be seen. Insects often have very localized populations.

Authors

    by
  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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