Page 124 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

BUTTERFLY CATERPILLARS

FAMILY Pieridae
DISTRIBUTION North America, including Mexico

HABITAT Montane meadows, alfalfa fields, gardens, parks, and pastures
HOST PLANTS Legumes, including Alfalfa (Medicago sativa), clover (Trifolium
spp.), vetch (Vicia spp.), Birdsfoot Trefoil (Lotus corniculatus),
and lupine (Lupinus spp.)

NOTE Caterpillar that can occur in millions around Alfalfa fields
CONSERVATION STATUS Not evaluated, but common

ADULT WINGSPAN
1¾–2 in (45–50 mm)
CATERPILLAR LENGTH
1³∕₈–1⁹∕₁₆ in (35–40 mm)
COLIAS EURYTHEME
ORANGE SULPHUR
122
BOISDUVAL, 1852

Before the Orange Sulphur caterpillar hatches, its white, spindle-
shaped egg turns yellow, then orange red. First instars consume
most of the eggshell after hatching. During the early instars, the
caterpillars skeletonize leaves by feeding between veins on both
sides of the midrib. Later instars consume entire leaves from
Actual size
the edge or tip. Development from egg hatch to pupation takes
about two to four weeks, but sometimes longer, depending on
the temperature and host plant. The caterpillar may overwinter
with reduced growth, although the species is unable to survive
the winter in northerly areas.

Colias eurytheme caterpillars are highly camouflaged on their host

The Orange Sulphur caterpillar is dark green plants, but natural enemies, including predatory bugs, parasitic
with a thick, spiracular, white stripe that has wasps, and birds, take a great toll on populations. Disease is also
intermittent red spots or lines. There are
large numbers of tiny, black dots and short, an important regulator of numbers. The caterpillars of all Colias
pale setae, and some individuals have a
vague dark stripe middorsally and a yellow species are very similar and easy to confuse. Increased acreages
dorsolateral stripe. The head is light green, of Alfalfa in the western United States have contributed to the
peppered with tiny, black dots.
great abundance of Orange Sulphurs in this region.