Page 132 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

BUTTERFLY CATERPILLARS

FAMILY Pieridae
DISTRIBUTION Western North America, from British Columbia to Arizona
HABITAT Low to high elevation coniferous forests

HOST PLANTS Pine (Pinus spp.), firs, such as Pseudotsuga menziesii and
Abies grandis, and Western Hemlock (Tsuga heterophylla)
NOTE Caterpillar that can defoliate pine forests
CONSERVATION STATUS Not evaluated, but common

ADULT WINGSPAN
1¾–2 in (45–50 mm)
CATERPILLAR LENGTH
1–1³∕₁₆ in (25–30 mm)
NEOPHASIA MENAPIA
PINE WHITE
130
(FELDER & FELDER, 1859)

Pine White caterpillars hatch in spring from eggs laid in
angled rows of 3 to 25 or more along conifer needles during

late summer and fall; the eggs then overwinter. The first instars
do not consume their own eggshells but do feed on adjacent
unhatched eggs. Early instars feed gregariously—typically four
to six on a needle, most with their heads toward the tip. Later
instars generally feed alone and are superbly camouflaged. Frass

is flicked away by young caterpillars, but older ones simply drop

it. When disturbed, young caterpillars may drop, suspended by
silk. Older caterpillars regurgitate food and wave their heads
around when threatened.

Development from egg hatch to pupation takes about two
months. Pine Whites normally exist at low population levels but
occasionally “explode” into major outbreaks, with caterpillars
defoliating large areas of forest, and butterflies so numerous that

they create the impression of a living snowstorm.

The Pine White caterpillar is dark conifer
green with numerous, small, white spots, and
distinct lateral (thick) and dorsolateral (thin),
yellowish or whitish stripes. There are two very
Actual size
short, taillike projections on the posterior
segment. The head is green with yellowish
spots, and the true legs are black.