Cloudless Sulphur butterfly Phoebis sennae. Yellow butterfly. Insect. Photograph taken by the author. Copyright © 2024 Now I Wonder. All rights reserved.

Whites And Sulphurs – family Pieridae

General Characteristics:

  • Species range in size from small to very large.
  • Full complement of six functional walking legs.
  • Adults flutter and fly rapidly.
  • Easy to find as adults visit huge variety of flowers and are widely distributed across the state.
  • Conspicuous thanks to bright white and yellow colors.
  • Some species are considered pests by farmers and home gardeners because their caterpillars feed on plants that humans grow for food.
    • Many species of whites feed on plants in the Mustard family (Brassicaceae), like cabbage, Brussels sprouts, cauliflower, and broccoli.
    • Many species of sulphurs feed on plants in the Pea family (Fabaceae).

To jump to the details for each individual species, click on the animal’s name in the list below.

To see the full list of every animal included in Now I Wonder, please visit the Index page.

Index Of Whites and Sulphurs By Name

Species

Cabbage White Butterfly

Pieris rapae

  • Formerly named Artogeia rapae
  • Native to Eurasia, humans accidentally introduced the Cabbage White butterfly (Pieris rapae) into Quebec in 1860 (Pyle 1981). It spread quickly across the United States and is now one of the most widely distributed butterfly species in North America.
    • Cabbage White butterflies even fly around in midtown Manhattan (Glassberg 2002).
  • Scientists introduced a parasitic wasp species (Cotesia glomerata) in an attempt to control the spread of the Cabbage White butterfly species in the United States.
    • Unfortunately, this wasp appears to have sent a northern, native species, the Mustard White butterfly (Pieris napi), into a severe decline (Wagner 2005).
  • This species also has the distinction of being one of the very few butterfly pests; its bright green caterpillars feed on cruciferous plants, such as broccoli and cabbage.

How To Identify Cabbage White Butterflies

  • Wingspan: 1.25 – 1.9 inches (3.1 – 4.8 cm)
  • Above:
    • Both forewings and hindwings are white and tipped with faint charcoal gray.
    • Forewings are dotted with at least one black spot.
    • The number of black wing spots vary by sex:
      • Males have one wing spot.
      • Females have two wing spots.
  • Below:
    • Color ranges from white to yellow.
    • Both sexes have only one black wing spot on the underside of their fore wings.
    • Hindwings are unmarked on both sexes.
  • The markings on early spring individuals may be paler than those seen on adults later in the flight season (Glassberg 1999).

How to Find Cabbage White Butterflies

  • Flight Season: Adults fly throughout the summer months, starting after the last hard frost in the spring and up to the first hard frost in the fall.
    • Usually early March through late November.
  • Cabbage White butterflies have three or more broods per season (Pyle 1981).
  • Look for Cabbage White butterflies in almost every habitat in North Carolina that is both sunny and contains plants in flower; they are both widely distributed and abundant.
    • They are especially easy to find in home gardens planted with Mustard family plants, including:
      • Cabbage
      • Broccoli
      • Cauliflower
      • Brussels sprouts
      • Kale
  • Cabbage White butterflies fly well but erratically and often swerve around.
    • They tend to fly higher than many butterflies when traveling from flower to flower.
    • They are easy to observe when they land but don’t stay perched for long; they feed quickly, then fly off to the next bloom.

How to Identify Cabbage White Eggs, Caterpillars, And Chrysalises

Eggs

  • Female Cabbage White butterflies lay pale, yellowish, vase-shaped eggs (Pyle 1981) one at a time on host plants (Daniels 2003).

Caterpillars

  • Cabbage White grow to about 0.75 inches (1.9 cm) long.
  • Lime-green bodies, with a faint, lengthwise yellow stripe, and broken yellow side stripes along their respiratory spiracles.
  • Covered in tiny bristles and tiny black spots that are only visible when viewed extremely close-up (Wagner 2005).
  • In home gardens, look for Cabbage White caterpillars on:
    • Cabbage
    • Broccoli
    • Brussels sprouts
    • Kale
    • Kohlrabi
    • Cultivated species of nasturtium (Pyle 1981)
  • Outside of home gardens, look for Cabbage White caterpillars on:
    • Wild plants in the Mustard family (Brassicaceae) like:
      • Early Yellowrocket (Barbarea verna)
      • Shepherd’s Purse (Capsella bursa-pastoris)
      • Wild Radish (Raphanus raphanistrum)
      • With over 350 genera and 3,000 species of mustard plants in the northern hemisphere, this butterfly species finds food easily.

Chrysalises

  • Cabbage White chrysalises are approximately 0.75 inches (1.9cm) long and are longer than they are wide.
  • Lime-green, speckled with green and tan (Pyle 1981), and have two lengthwise ridges that run from the bottom point to the thickest middle section and end in brown-colored peaks.
  • Lie against the surfaces of plant leaves, anchored at both ends with silk.

Clouded Sulphur Butterfly

Colias philodice

  • Clouded Sulphur butterflies love alfalfa, and can become serious pests when its population gets too dense in a given area.
  • Another common name for the Clouded Sulphur butterfly is “Common Sulphur” (Pyle 1981).
    • The word “sulphur” can be spelled either with a “ph” or “f”, as in “sulfur”. The International Union of Pure and Applied Chemistry (IUPAC) made “sulfur” the preferred spelling in 1990, but many books and field guides still use the old spelling. Either one can be considered correct spelling for this butterfly’s common name.
  • Clouded Sulphur butterflies (Colias philodice) sometimes mate with Orange Sulphur butterflies (Colias eurytheme) (Opler and Malikul 1992).
    • The ranges and food plants of these two species overlap and they look almost identical. In fact, it can be very hard for humans to tell the two types of butterflies apart in real life.
    • The butterflies themselves don’t really have this problem. Male Clouded Sulphur butterflies produce special chemicals called pheromones. Orange Sulphurs don’t make the same chemicals (Grula et al. 1980). Females of each species identify males of their own species by how the males smell.

How To Identify Clouded Sulphur Butterflies

  • Wingspan: 1.4 – 2.0 inches (3.6 – 5.0 cm)
  • Clouded Sulphur butterflies can be hard to identify for two reasons:
    • Males and females are sexually dimorphic; they look different from each other.
    • Adults are “seasonally variable”; their appearance varies slightly with temperature:
      • Spring and fall adults are small and greenish-yellow (Pyle 1981).
      • Summer adults are large and bright yellow.
  • Above:
    • Males have bright sulphur-yellow wings with sharply defined, solid black borders.
    • Females can be either yellow or white with yellow-spotted black borders.
    • Both sexes have a black wing spot on their forewings.
    • Hindwings have an orange spot in the center.
  • Below:
    • Green-yellow overall with a faint row of dark spots.
    • Male forewings show a single black spot.
    • Female forewings may have a small, pinkish wing spot.
    • Hindwings have two spots each; one large and one small. Both spots are silvery and surrounded by thin, red rims.
    • Pink wing fringe.
    • Hindwings have a widely spaced single row of tiny brown spots.
  • Clouded Sulphurs almost always close their wings when they land.

How to Find Clouded Sulphur Butterflies

  • Flight Season: Adults fly between late March and mid-November in North Carolina.
    • Female Clouded Sulphur butterflies lay eggs throughout this time so many broods develop over the summer.
  • Look for Look for Clouded Sulphur butterflies anywhere lots of flowers bloom. You can find them in waste lots, meadows, farm fields, and along roadsides.
    • They especially love sunny areas where clovers, vetch, and other legumes grow.
    • Favorite nectar sources include:
      • Blue Vetch (Vicia cracca)
      • Wild Lupine (Lupinus perenis)
      • White Sweet Clover (Melitotus alba)
      • Red Clover (Trifolium pratense)

How to Identify Clouded Sulphur Eggs, Caterpillars, And Chrysalises

Eggs

  • Female Clouded Sulphur butterflies lay their eggs one at a time on clover plants (Pea family Fabaceae).
  • Clouded Sulphur butterfly eggs are pale, yellow-green when first laid but turn red after a day or two, then gray before they hatch (Wagner 2005).

Caterpillars

  • Clouded Sulphur caterpillars are bluish-green and about 1.4 inches (3.5cm) long (Wagner 2005). A single thin, cream-colored stripe runs lengthwise down their sides. The stripe may include pink or red sections and be edged in black or dark green.
  • Look for Clouded Sulphur caterpillars on plants in the Pea family (Fabaceae) especially:
    • White Sweet Clover (Melitotus alba)
    • Red Clover (Trifolium pratense)
    • Dutch Clover (Trifolium repens).
  • This species feeds on Alfalfa (Medicago sativa), which both grows as a wildflower in North Carolina after it escaped cultivation (Daniels 2003) and as a human food crop. Clouded Sulphur caterpillars can become real pests to alfalfa farmers.

Chrysalises

  • Chrysalises are green.
  • Individual Clouded Sulphurs survive North Carolina’s winters as pupae. Their leathery, waterproof chrysalises protect them from freezing to death.
    • Once spring arrives, the pupae emerge as adults and start to breed.
    • Mild temperatures in mid-winter sometimes trick them into emerging too soon (Opler and Malikul 1992).

Cloudless Sulphur Butterfly

Phoebis sennae

  • Also called “Cloudless Giant Sulphurs”.
  • Cloudless Sulphur butterflies have unusually long probosces, the coiled, tubular mouthpart with which butterflies siphon flower nectar for food.
    • For example, the probosces of P. sennae are nearly 0.4 inches (1 cm) longer than those of a Brush-footed butterfly species, the Gulf Fritillary Butterfly (Agraulis vanillae).
    • This allows Cloudless Sulphurs to access nectar from flowers whose nectaries are so deep they can’t be reached by other butterflies (Daniels 2003).
    • Why is this so important?
      • Lipids (otherwise known as fat) are an important source of energy for insects.
      • Cloudless Sulphurs have less energy stored than Gulf Fritillaries.
        • Lipids make up only 6% of the mass of a newly emerged adult Cloudless Sulphur Butterfly. In comparison, a Gulf Fritillary’s mass is 13-16% lipid (May 1992).
      • All things being equal, a Cloudless Sulphur butterfly will starve to death faster than a Gulf Fritillary butterfly.
      • But, thanks to their extra-long probosces, Cloudless Sulphur butterflies can feed from a greater variety of flowers than can Gulf Fritillaries, and can feed with greater efficiency; more than four times the efficiency of Gulf Fritillaries (May 1992).
  • The word “sulphur” can be spelled either with a “ph” or “f”, as in “sulfur”. The International Union of Pure and Applied Chemistry (IUPAC) made “sulfur” the preferred spelling in 1990, but many books and field guides still use the old spelling. Either one can be considered correct spelling for this butterfly’s common name.

How To Identify Cloudless Sulphur Butterflies

  • Wingspan: 2.1 – 2.75 inches (5.3 – 7 cm).
  • Perch with their wings tightly closed.
  • Above:
    • Both forewings and hindwings are clear, bright sulphur yellow.
      • Males are brighter yellow than females.
    • Male forewings are unbroken yellow.
    • Female forewings each have a single, small, brown-rimmed wing spot and a thin, broken brown band along the wing edge.
  • Below:
    • Appearance varies by sex (“sexually dimorphic”)
    • Male Cloudless Sulphur butterflies:
      • Have a single pale spot on their forewings and hindwings.
      • Are more uniformly colored than females; wings range in color from tan to yellow.
    • Female Cloudless Sulphur butterflies:
      • Are brighter in color than males.
      • Mottled, with scattered dark marks.
      • Wings range in color from greenish-white to pinkish-orange to bright yellow.
      • Can have multiple small silver-white spots on both forewings and hindwings.

How to Find Cloudless Sulphur Butterflies

  • Flight Season: Early March and late November in North Carolina.
    • Cloudless Sulphur females lay eggs throughout this time so many broods develop over the summer.
  • Cloudless Sulphur butterflies live year-round in Florida and the southernmost states.
    • As temperatures rise in the spring, millions of these large, bright yellow insects venture north, reaching North Carolina in early spring, and sometimes making it as far north as Maine and southern Canada.
    • However, the northernmost butterflies die out in the fall; they don’t travel back south (Pyle 1981).
    • More southern populations travel south in fall to overwinter (Daniels 2003).
  • Cloudless Sulphur Butterflies seem to be especially fond of puddling and can often be seen grouped together around mud puddles and disturbed ground.
  • Look for Cloudless Sulphur Butterflies in any kind of open space with lots of blooming flowers and sunlight, like meadows, along roadsides, and in home gardens.
    • They favor lantana, bougainvillea, Turk’s Cap (Lilium superbum), and hibiscus (Opler 1994).

How to Identify Cloudless Sulphur Eggs, Caterpillars, And Chrysalises

Eggs

  • Female Cloudless Sulphur butterflies lay tiny pitcher-shaped eggs that start out pale and turn pale orange over time (Pyle 1981). They lay eggs one at a time on the leaves of a host plant (Daniels 2003).

Caterpillars

  • When young, Cloudless Sulphur caterpillars are yellowish-green with a thick yellow side stripe.
  • Green heads sprinkled with tiny black spots.
  • Body segments are covered in tiny black spots ringed in pale blue.
  • As the caterpillars grow and age towards metamorphosis, their bodies turn bright yellow with widely spaced black side-to-side stripes (Glassberg 2002)
  • During the day, Cloudless Sulphur caterpillars hide within leaf shelters they construct by pulling leaves together with silk (Pyle 1981).
  • Look for Cloudless Sulphur caterpillars on plants in the Pea family (Fabaceae) like:
    • Littleleaf Sensitive Briar (Mimosa microphylla)
    • Partridge Pea (Chamaecrista cinerea)
    • Red Clover (Trifolium pratense)
    • Dutch Clover (Trifolium repens)
    • Wild Senna (Senna hebecarpa)
    • Java-bean (Senna obtusifolia)

Chrysalises

  • Chrysalises are elongated, pointed at the ends, and bulge in the middle. They are pink or green with yellow or green stripes (Pyle 1981).