Pieris rapae

(Linnaeus, 1758)

small white, cabbage white, cabbage butterfly, small cabbage white, imported cabbageworm (larval stage), white butterfly (New Zealand)

is a small to medium-sized in the Pieridae, native to Europe and Asia and introduced to North America, Australia, New Zealand, and Hawaii. are white with black wing markings; females bear two additional black spots on the forewings. The is a significant agricultural pest in its larval stage, known as the imported cabbageworm, feeding on cruciferous crops. It has been extensively studied for its responses to climate change, with long-term data showing progressively earlier spring in North America.

Pieris rapae by the Smithsonian. Used under a CC0 license.

Pronunciation

How to pronounce Pieris rapae: //ˈpiː.ɛ.rɪs ˈræ.peɪ//

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Identification

Distinguished from Pieris brassicae (large white) by smaller size and lack of black band at forewing tip. Distinguished from Pieris napi (green-veined white) by wing pattern and pupal extending far beyond antennal sheath. Females distinguished from males by presence of two black forewing spots.

Images

Habitat

Open areas with diverse plant associations including towns, agricultural fields, gardens, and natural valley bottoms. Has been observed entering small forest clearings. Avoids cool, shaded woodlands for oviposition even when plants are present. Absent or scarce in desert and semidesert regions except irrigated areas.

Distribution

Native to Europe, Asia, and North Africa. Introduced to eastern North America (Quebec, ~1860), Hawaii (1897), New Zealand (~1930), and Australia (1937). Present across North American life zones from Lower Austral/Lower Sonoran to Canada. Not found north of Canadian life zone or on Channel Islands off southern California. Absent from South America.

Seasonality

In Britain, two periods: April–May and July–August. In North America, continuously brooded from early spring until hard freeze in fall. First flight in central California has ranged from January 1 to February 22 since 1972, averaging about January 20, with trend toward earlier emergence due to climate warming.

Diet

feed on nectar, preferring purple, blue, and yellow flowers. Larvae feed on plants containing glucosinolates, primarily Brassicaceae including cultivated cabbage, kale, bok choy, broccoli, radish, and wild mustards such as charlock (Sinapis arvensis) and hedge mustard (Sisymbrium officinale).

Host Associations

Brassica oleracea - larval cultivated cabbage
Brassica rapa - larval field mustard; has UV
Brassica juncea - larval
Brassica napus - larval rapeseed
Brassica nigra - larval black mustard
Sinapis arvensis - larval charlock, wild mustard
Sisymbrium officinale - larval hedge mustard
Raphanus sativus - larval cultivated radish
Raphanus raphanistrum - larval wild radish
Nasturtium officinale - larval watercress
Capsella bursa-pastoris - oviposition siteshepherd's purse; females oviposit but larvae refuse
Lunaria annua - larval honesty; retards larval growth
Thlaspi arvense - larval field pennycress; larvae grow slowly or refuse
Tropaeolum majus - larval nasturtium
Hirschfeldia incana - larval shortpod mustard; allowing summer survival
Lepidium latifolium - larval peppergrass; in western Great Basin

Life Cycle

laid singly on plant leaves. Larva hatches and consumes eggshell before feeding on host foliage, boring into cabbage to feed on new sprouts. Five larval instars; development rate temperature-dependent, optimal near 30–35°C under field conditions. occurs on substrate matching larval background color. Overwinters as pupa. Multiple per year in favorable climates.

Behavior

, flying throughout day except early morning and evening. Males patrol around plants seeking females; upon encountering female, zigzag pattern followed by attempt to mate by grasping forewings with legs. Unreceptive females reject by flying vertically or raising with wings spread. Males engage in mud-puddling for sodium uptake, correlated with increased reproductive success. Adults capable of long-distance flight, observed moving up to 12 km in single flight; average female daily movement ~0.7 km. Females follow linear flight paths when searching for host plants, abandoning linearity when foraging for nectar. Oviposition preferentially on isolated or peripheral plants rather than dense patches. Larvae rest on undersides of leaves but feed mostly during day, dispersing damage across plant to reduce visual cues to . Larvae show flower constancy in foraging, with learning curve for nectar location.

Ecological Role

Herbivore of Brassicaceae; significant agricultural pest causing damage valued in hundreds of thousands of dollars. Larvae serve as for Cotesia rubecula, Cotesia glomerata, and flies Phryxe vulgaris, Epicampocera succinata. Pupae parasitized by Pteromalus puparum. Prey for birds including house sparrow, goldfinch, and skylark in urban environments; more significant in rural areas. serve as .

Human Relevance

Major pest of cruciferous vegetable crops worldwide; larvae known as imported cabbageworm. Subject of long-term phenological research in California since 1972, documenting climate change effects through 'Beer-for-a-' contest tracking first spring . Used as model organism in studies of insect-plant chemical , - interactions, and urbanization effects on functional traits.

Similar Taxa

Pieris brassicaeLarger size; black band at forewing tip rather than discrete black spots; larvae sequester glucosinolates making them distasteful to (P. rapae larvae are palatable)
Pieris napiGreen-veined wing pattern; pupal extends only short distance beyond antennal sheath (vs. far beyond in P. rapae)

More Details

Climate change response

Long-term data from central California (1972–present) document progressively earlier spring , averaging approximately one week earlier than 30 years ago. First dates correlate with regional temperature trends.

Pupal color polyphenism

Pupal color determined by light environment during approximately 24-hour prepupal wandering stage. Yellow wavelengths produce green pupae, blue wavelengths produce brown pupae. This background matching is adaptive for . Diapausing pupae show greater tendency toward brown coloration.

Biochemical adaptation to host plants

Unlike many herbivores, P. rapae is immune to isothiocyanate forming reaction from glucosinolates due to specific biochemical , allowing exploitation of Brassicaceae defenses. This adaptation appears to have driven coevolutionary dynamics with plants.

Subspecies

Nominate P. r. rapae in Europe; P. r. crucivora in Asia. Additional subspecies include atomaria, eumorpha, leucosoma, mauretanica, napi, novangliae, and orientalis.