Pontia protodice

Geographic Range

Known as the southern cabbageworm in its larval stage, Pontia protodice, the checkered white butterfly, is commonly found across the United States into northern Mexico. Temporary populations occur as the adults move North, with some populations appearing in southern Canada. These are often seasonal populations which fall South again in fall and winter. The species does not occur in the Pacific Northwest nor the majority of New England, with highly erratic populations east of the Appalachians. ("Species Assessment for Checkered white Butterfly", 2014)


Checkered whites are found mainly in open, dry or sandy disturbed habitats and are not found in forested or shady areas. They commonly thrive in tundras, grasslands, deserts and steppes, and inhabit roadsides, railroad beds, empty or sandy lots, beach dunes, fields and pastures. Although they have been reported from 76 m to 3764 m in elevation, checkered whites are most common below 3048 m, and typically reproduce below 2743 m. ("Montana Field Guide", 2021; Opler and Krizek, 1984; Shapiro, 1992)

  • Range elevation
    76 to 3764 m
    249.34 to 12349.08 ft
  • Average elevation
    below 3048 m

Physical Description

Southern cabbageworms grow up to 3.5 cm and have 4 long yellow stripes with gray to gray-blue coloration between. Their bodies are dotted with numerous black spots from which small hairs, called setae, protrude. Males and females can be differentiated as males have immaculate hind wings and forewings with 1 to 3 black marks. Females are much more heavily patterned, with up to 50 percent of their forewings and the outer margins of their hind wings covered in black marks. Checkered whites can also take on slight variations to their patterns when they emerge in the summer versus the spring and fall. Spring or fall butterflies, the short-day form, get less sunlight during their development which creates more distinct green-gray veins on the ventral side of their wings and lighter patterns than the long-day form. Checkered whites have a wingspan between 3.5 to 6.3 cm, the males being slightly smaller than the females and the short-day form being slightly smaller on average. Visually similar to Pieris rapae. (Capinera, 2001; "Checkered White", 2021; Opler and Krizek, 1984; Wagner, 2005)

  • Sexual Dimorphism
  • female larger
  • sexes colored or patterned differently
  • Range wingspan
    3.5 to 6.3 mm
    0.14 to 0.25 in


Eggs of P. protodice are barrel-shaped with deep ridges. They begin yellow and turn orange as they mature. The eggs are usually laid singly on the flowers or stems of host plants. Larvae hatch after 4 to 7 days and transition through five instars and four molts before pupating after an average of 15 to 16 days. The chrysalids are green or brown with black spotting and yellow-white angular lines on small ridges. The adults emerge after 10 to 15 days, except for the late season generations, which overwinter as pupae. Males often emerge earlier than females and adults typically live up to 10 days. Pupae resemble those of Pieris rapae. (Hall, 2015; "Montana Field Guide", 2021)


Male checkered whites emerge before the females and begin patrol flights in search of mates. Courtship takes about 3 seconds before mating ensues, and males regularly lead females on post-nuptial flights to avoid competition from other males. On these flights, males transfer a spermatophore to the female. Checkered whites are known to produce about 50 eggs each time they mate, and females have the potential to mate more than once. This process usually happens the day of emergence for the females, but females will migrate if local populations are dense. New females or those with small spermatophores have been observed fluttering around males to encourage courtship and mating. Short-day form butterflies typically have lower fitness levels, and may not produce as many eggs. ("Montana Field Guide", 2021; Opler and Krizek, 1984; "Species Assessment for Checkered white Butterfly", 2014)

Sexual maturity is reached upon emergence from the chrysalis for both males and females. Females lay around 50 eggs each, and solitary larvae hatch approximately 3 days later. There is no parental care. (Opler and Krizek, 1984)

  • Breeding interval
    Females may mate more than once in their lifetime.
  • Breeding season
    Seasonal breeding occurs between early spring and fall.
  • Average eggs per season
  • Average time to independence
    0 minutes
  • Average age at sexual or reproductive maturity (female)
    upon emergence, approx. 20 days
  • Average age at sexual or reproductive maturity (male)
    upon emergence, approx. 20 days

Checkered whites do not provide care for their offspring.

  • Parental Investment
  • no parental involvement


Checkered whites live approximately 30 days, 3 to 5 are spent in eggs, 14 to 16 days are spent in the larval stage, 10 to 14 days are spent as pupae and 6 to 10 days as adults. Short-day form butterflies typically have shorter lives, and late broods overwinter as pupae. ("Montana Field Guide", 2021)

  • Range lifespan
    Status: wild
    6 to 10 days
  • Typical lifespan
    Status: wild
    6 to 10 days


Pontia protodice are solitary, beginning with eggs laid singly. They have 3 flights per year with a 4th partial flight as late as November. This butterfly can reach high elevations and northern regions, though populations at these locations are often non-breeding or erratic and migratory. Checkered whites are day active. ("Species Assessment for Checkered white Butterfly", 2014)

Communication and Perception

Like most butterflies, checkered whites respond to visual stimuli through compound eyes. They do not, however, rely on coloration or patterns to communicate. Instead, sexes identify one another through UV reflectivity. ("Species Assessment for Checkered white Butterfly", 2014)

Food Habits

Eggs are laid on larval host plants, which include mostly mustards in Brassicaceae. Many plants the southern cabbageworms consume are crop species, including cabbage, broccoli, cauliflower, turnips and radishes. The larva prefer to consume flowers and buds, but will eat leaves. On cabbage they tend to prefer the outer leaves. Adults are nectar feeders, and have been know to feed from over 50 species of plants. ("Montana Field Guide", 2021; "Species Assessment for Checkered white Butterfly", 2014)

  • Plant Foods
  • leaves
  • nectar
  • flowers


Known predators include robber flies (Proctacanthus milbertii) and robins (Turdus migratorius) and introduced parasitoid flies. Additionally, the introduced biocontrol agent Costesia glomerata, intended to control P. rapae, preys upon P. protodice. Other predators may include assassin bugs as well as other parasitoids and birds. ("Pontia protodice (Checkered White)", 2020; "Species Assessment for Checkered white Butterfly", 2014)

Ecosystem Roles

Southern cabbageworms, the larvae, play a role as a minor agricultural pest. They often feed on cabbage, cauliflower, broccoli, radishes and turnips. However, they also feed on wild mustards, and have been largely replaced as a pest by the imported cabbageworm. Additionally, southern cabbageworms tend to feed on outer leaves of crops such as cabbage and broccoli, and are therefore less harmful to crops than P. rapae. The adults, checkered whites, are solely nectar feeders and may play a role in pollination based on the habits of similar species. (Capinera, 2001)

Commensal/Parasitic Species
  • parasitoid flies and wasps including C. glomerata.

Economic Importance for Humans: Positive

Checkered whites may be pollinators based on similar species including P. rapae. However, there is not enough literature on the subject.

  • Positive Impacts
  • pollinates crops

Economic Importance for Humans: Negative

Southern cabbageworms are considered a minor agricultural pest. (Capinera, 2001)

  • Negative Impacts
  • crop pest

Conservation Status

Checkered whites have seen a population decline, with a heightened rate since the release of biocontrol agent C. glomerata targeted at P. rapae. Other reasons for decline include pesticides and herbicides, habitat loss and fragmentation, development, light-pollution, over-grazing, land clearing, erosion, sea-level rise and irregular fire seasons. There is little conservation action currently, howver, checkered whites have been identified as a second-priority species vulnerable to climate change by the New York State Department of Environmental Conservation and The Nature Conservancy. ("Species Assessment for Checkered white Butterfly", 2014)


Claire Walther (author), Special Projects, Amy Bagby (), Colorado State University.



living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map


living in landscapes dominated by human agriculture.


having coloration that serves a protective function for the animal, usually used to refer to animals with colors that warn predators of their toxicity. For example: animals with bright red or yellow coloration are often toxic or distasteful.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

  1. active during the day, 2. lasting for one day.

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature


union of egg and spermatozoan


an animal that mainly eats leaves.


An animal that eats mainly plants or parts of plants.

internal fertilization

fertilization takes place within the female's body


A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.


This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.


reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.


chemicals released into air or water that are detected by and responded to by other animals of the same species


Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous).

seasonal breeding

breeding is confined to a particular season


offspring are all produced in a single group (litter, clutch, etc.), after which the parent usually dies. Semelparous organisms often only live through a single season/year (or other periodic change in conditions) but may live for many seasons. In both cases reproduction occurs as a single investment of energy in offspring, with no future chance for investment in reproduction.


reproduction that includes combining the genetic contribution of two individuals, a male and a female


lives alone


mature spermatozoa are stored by females following copulation. Male sperm storage also occurs, as sperm are retained in the male epididymes (in mammals) for a period that can, in some cases, extend over several weeks or more, but here we use the term to refer only to sperm storage by females.


living in residential areas on the outskirts of large cities or towns.


that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).


Living on the ground.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.


A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.


A terrestrial biome with low, shrubby or mat-like vegetation found at extremely high latitudes or elevations, near the limit of plant growth. Soils usually subject to permafrost. Plant diversity is typically low and the growing season is short.


uses sight to communicate


Metalmark Web and Data. 2021. "Checkered White" (On-line). Butterflies and Moths of North America. Accessed July 14, 2021 at https://www.butterfliesandmoths.org/species/Pontia-protodice.

Montana Natural Heritage Program. 2021. "Montana Field Guide" (On-line). Checkered white - Pontia protodice. Accessed July 15, 2021 at https://fieldguide.mt.gov/speciesDetail.aspx?elcode=IILEPA1030.

2020. "Pontia protodice (Checkered White)" (On-line). World Species. Accessed July 16, 2021 at https://worldspecies.org/ntaxa/713343#predator.

New York State Department of Environmental Conservation. Species Assessment for Checkered white Butterfly. Section 182.2(i) of 6NYCRR Part 182. New York: New York State Department of Environmental Conservation. 2014. Accessed July 14, 2021 at https://www.dec.ny.gov/docs/wildlife_pdf/sgcncheckwhite.pdf.

Capinera, J. 2001. Handbook of Vegetable Pests. New York: Academic Press.

Hall, D. 2015. "southern cabbageworm (larva), checkered white (adult) scientific name: Pontia (Pieris) protodice (Boisduval & Leconte) (Insecta: Lepidoptera: Pieridae: Pierinae)" (On-line). Featured Creatures - Entomology and Nematology. Accessed July 15, 2021 at https://entnemdept.ufl.edu/creatures/veg/leaf/checkered_white.htm.

Opler, P., G. Krizek. 1984. Butterflies East of the Great Plains. Baltimore, Maryland: The Johns Hopkins University Press.

Shapiro, A. 1992. Twenty Years of Fluctuating Parapatry and the Question of Competitive Exclusion in the Butterflies Pontia Occidentalis and P. Protodice (Lepidoptera: Pieridae). Journal of the New York Entomological Society, vol. 100, no. 2: 311-319. Accessed July 15, 2021 at www.jstor.org/stable/25009966.

Wagner, D. 2005. Caterpillars of Eastern North America. New Jersey: Princeton University Press.