Pontia sisymbrii

(Boisduval, 1852)

Spring White, California White, Colorado White

Pontia sisymbrii, commonly known as the Spring , is a small in the . It is one of the earliest butterflies to appear in spring in western North America, often emerging before the vernal equinox. The exhibits , with males typically white and females sometimes yellowish. It is closely associated with mustard family plants and has a single annually at higher elevations, with two generations at lower elevations.

Pronunciation

How to pronounce Pontia sisymbrii: //ˈpɒntiə sɪˈsɪmbri.aɪ//

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Identification

Distinguished from similar checkered (Pontia beckerii, P. protodice, P. occidentalis) by dark pattern on underside of hind . In , difficult to separate from Large Marble (Euchloe ausonides) and Cabbage White (); perched specimens can be identified by underside wing pattern. earlier in season than most other white in its range.

Appearance

Small with wingspan of 31-40 mm. Upper surface mostly with small black markings; females may be yellowish. Underside of hind wings shows dark pattern of , a identification feature. Some specimens have nearly pure white upper surface.

Habitat

Foothills and higher elevations in mountainous areas. Frequents canyon bottoms and ridge tops where males hilltop to intercept females. Associated with prairie and dry meadow where plants grow.

Distribution

Western North America: most of U.S. west of Rocky Mountains, including mountains of Arizona and New Mexico; extends east into extreme western South Dakota and Nebraska Panhandle; south-central British Columbia; in Oregon and Washington, found east of Cascade Range and in Olympic Mountains. Present in western Canada and United States.

Seasonality

Early spring : on from late February through end of June. One annually at higher elevations, two generations at lower elevations. Among first to appear in spring, often before vernal equinox in Colorado Range.

Host Associations

  • Caulanthus - larval Brassicaceae
  • Streptanthus - larval Brassicaceae; S. breweri has orange spots that mimic , deterring
  • Sisymbrium altissimum - larval Brassicaceae; hedge mustard
  • Arabis glabra - larval Brassicaceae; rock-cress
  • Arabis furcata - larval Brassicaceae; rock-cress
  • Arabis holboelli - larval Brassicaceae; rock-cress
  • Descurainia - larval Brassicaceae; tansy-mustard

Life Cycle

Females single on stems and foliage of plants. Eggs hatch in approximately one week. progress through five ; older are and -gray vertically striped with black speckles. occurs in that is mottled or black with texture. Unlike most pierids, chrysalis lacks and attaches only at tail end using hooks fastened to silk pad.

Behavior

Males exhibit , flying along ridge tops and buttes to intercept females flying up from below. Wary and easily startled; perches frequently but difficult to approach for photography. Can be found in canyon bottoms where topography funnels females.

Ecological Role

as ; as . Larval feeding on Brassicaceae. Potential for various and .

Human Relevance

None significant; not a . Serves as early-season indicator of spring arrival in western North America.

Similar Taxa

  • Pontia protodiceCheckered ; similar in appearance but with different distribution and seasonality; P. sisymbrii earlier and has more restricted western range
  • Pontia beckeriiBecker's ; similar checkered white pattern but different geographic range and preferences
  • Pontia occidentalisWestern ; similar appearance but differs in distribution and subtle pattern details
  • Euchloe ausonidesLarge Marble; extremely difficult to distinguish in ; perched specimens separable by underside pattern and marble-like on underside of E. ausonides
  • Pieris rapaeCabbage ; similar white coloration but lacks dark pattern on underside; different and seasonality

More Details

Subspecies

Five recognized: P. s. sisymbrii, P. s. elivata (Barnes & Benjamin, 1926), P. s. flavitincta (Comstock, 1924), P. s. nigravenosa (Austin & Emmel, 2003), P. s. transversa (Holland, 1995)

Egg mimicry

In northern California, Streptanthus breweri (Brewer's Jewelflower) produces orange spots that mimic , causing females to avoid these plants; this reduces risk as are known to cannibalize each other when too numerous on one

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Sources and further reading