$7.95
<—2 in stock
The Western White, Pontia occidentalis, is a small, milky white butterfly with a wingspan of about 38 to 53 mm (1.5 to 2.1 inches). The upperside has a black bar at the end of the forewing cell, a dark band of spots near the wing edge with lighter gray V-shaped marks beyond it, and the veins are penciled with black. The underside, which is what you see in the photo, is different. The tip of the forewing and the whole hindwing are white with every vein outlined in broad gray-green scaling, which is strongest on spring butterflies. It is never bright green or heavy. The Checkered White, Pontia protodice, is the hardest look-alike, because its spring form also has green-veined hindwings. The best clue is on the upperside of the forewing, where the Western White has its spots near the wing edge joined into a connected arc, while the Checkered White has them separate. The Margined White, Pieris marginalis, is the other look-alike. It also has green-edged veins underneath, but the edges are wide and soft, its summer form is plain white above and below, and its spring form has only a black-tipped forewing, with no black bar at the end of the forewing cell. It prefers moist forests and streamsides instead of open dry country.
The Western White lives in open country, including mountain meadows, dry forest openings, hilltops and ridges, open plains, fields, roadsides, and railroad yards. It ranges from Alaska and the Yukon south to central California, northern Arizona, and northern New Mexico, and east across Canada to central Ontario and the Great Lakes region. On the Great Plains it is found mostly in the western half of South Dakota and in extreme western Nebraska, and it has been spreading east. It is on the South Dakota Game, Fish and Parks butterfly checklist, and it has been recorded in Fall River County. Some of our specimens were collected near Hot Springs, South Dakota.
Males patrol hilltops and ridges through the day looking for females. This habit is called hilltopping, and it helps males and females find each other in open country. Adults visit flowers for nectar, including thistles, asters, goldenrods, clovers, and rabbitbrush, and they also sip at damp mud. The butterfly does not migrate.
Complete metamorphosis (egg, larva, pupa, adult). There is one flight in the far north and at high elevations, and two or three flights a year in the south and at lower elevations, from late spring into early fall. The female lays her eggs one at a time on the leaves, stems, and flower buds of plants in the mustard family, such as rockcress, peppergrass, tansy mustard, flixweed, tumble mustard, and wild mustards. The caterpillars have blue and yellow stripes down the back and feed on the flowers, buds, and seed pods more than the leaves. They build no nest. The eggs hatch in about 3 days, and the caterpillars grow up and pupate in about 15 to 20 days in warm weather. Adults emerge about 10 days later. The butterfly spends the winter as a chrysalis.
The Western White is not considered a pest. Its caterpillars, called checkered white cabbageworms, feed on wild mustards and sometimes on cultivated crops in the mustard family such as canola, but the Canola Council of Canada reports that cabbageworm numbers have not been high enough to cause economic damage in canola on the Prairies. It is considered secure globally and needs no special conservation management. Because its caterpillars feed mostly on wild mustards, it is a minor player in gardens and fields.
This preserved specimen educates on butterfly identification and hilltopping behavior, suitable for displays or studies. Check it out on BugGuide! https://bugguide.net/node/view/13381
The Western White, Pontia occidentalis, is a small, milky white butterfly with a wingspan of about 38 to 53 mm (1.5 to 2.1 inches). The upperside has a black bar at the end of the forewing cell, a dark band of spots near the wing edge with lighter gray V-shaped marks beyond it, and the veins are penciled with black. The underside, which is what you see in the photo, is different. The tip of the forewing and the whole hindwing are white with every vein outlined in broad gray-green scaling, which is strongest on spring butterflies. It is never bright green or heavy. The Checkered White, Pontia protodice, is the hardest look-alike, because its spring form also has green-veined hindwings. The best clue is on the upperside of the forewing, where the Western White has its spots near the wing edge joined into a connected arc, while the Checkered White has them separate. The Margined White, Pieris marginalis, is the other look-alike. It also has green-edged veins underneath, but the edges are wide and soft, its summer form is plain white above and below, and its spring form has only a black-tipped forewing, with no black bar at the end of the forewing cell. It prefers moist forests and streamsides instead of open dry country.
The Western White lives in open country, including mountain meadows, dry forest openings, hilltops and ridges, open plains, fields, roadsides, and railroad yards. It ranges from Alaska and the Yukon south to central California, northern Arizona, and northern New Mexico, and east across Canada to central Ontario and the Great Lakes region. On the Great Plains it is found mostly in the western half of South Dakota and in extreme western Nebraska, and it has been spreading east. It is on the South Dakota Game, Fish and Parks butterfly checklist, and it has been recorded in Fall River County. Some of our specimens were collected near Hot Springs, South Dakota.
Males patrol hilltops and ridges through the day looking for females. This habit is called hilltopping, and it helps males and females find each other in open country. Adults visit flowers for nectar, including thistles, asters, goldenrods, clovers, and rabbitbrush, and they also sip at damp mud. The butterfly does not migrate.
Complete metamorphosis (egg, larva, pupa, adult). There is one flight in the far north and at high elevations, and two or three flights a year in the south and at lower elevations, from late spring into early fall. The female lays her eggs one at a time on the leaves, stems, and flower buds of plants in the mustard family, such as rockcress, peppergrass, tansy mustard, flixweed, tumble mustard, and wild mustards. The caterpillars have blue and yellow stripes down the back and feed on the flowers, buds, and seed pods more than the leaves. They build no nest. The eggs hatch in about 3 days, and the caterpillars grow up and pupate in about 15 to 20 days in warm weather. Adults emerge about 10 days later. The butterfly spends the winter as a chrysalis.
The Western White is not considered a pest. Its caterpillars, called checkered white cabbageworms, feed on wild mustards and sometimes on cultivated crops in the mustard family such as canola, but the Canola Council of Canada reports that cabbageworm numbers have not been high enough to cause economic damage in canola on the Prairies. It is considered secure globally and needs no special conservation management. Because its caterpillars feed mostly on wild mustards, it is a minor player in gardens and fields.
This preserved specimen educates on butterfly identification and hilltopping behavior, suitable for displays or studies. Check it out on BugGuide! https://bugguide.net/node/view/13381
