Checkered White
Pontia protodice
Common White
Description 1 1/4-1 3/4" (32-44 mm). Generally white above with charcoal or brown markings; HW veins below lined with brown- or olive-green. Female more heavily marked than male; spring brood more marked than summer - heavily checkered with charcoal above and lined with olive below. Summer male nearly immaculate white except for black cell spot above and tan tracery below. All gradations in between can occur.
Similar Species Western White has similar variations but summer male greenish-veined beneath and summer female more darkly checkered. In most of range best separated by habitat; at eastern base of Cascade and Sierra Nevada mountains only an expert can distinguish species.
Life Cycle Yellow spindle-shaped eggs. Caterpillar becomes blue-green, black-speckled, and downy with 4 lengthwise yellow stripes. Blue-gray chrysalis has black speckles; overwinters in California.
Host plants include many kinds of native and alien crucifers as well as some capers, such as bee plant (Cleome).
Flight Early spring-late fall in several broods; year-round in parts of California.
Habitat Mostly lowland open spaces, especially disturbed areas, fields, vacant lots, railroad yards, and other weedy plots.
Range North America and n. Mexico from lower margins of Canada southward; absent from most of Pacific Northwest. Scarcer in East.
Discussion The distributions of native white butterflies have probably changed considerably since pre-colonial times, possibly due in part to competition from the introduced Cabbage White. However, these changes may be caused to a greater extent by the expansion and contraction of various habitats due to use or disuse by people. The Checkered White is thought to be less common now in its native East and more abundant in disturbed parts of the West, into which it has spread on the heels of agriculture. Although it can reach enormous numbers, it seldom approaches the abundance of the Cabbage White.
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