Page 229 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

BUTTERFLY CATERPILLARS

FAMILY Nymphalidae
DISTRIBUTION Western North America, from British Columbia to Washington
State, Idaho, Oregon, Nevada, and California
HABITAT Mountains, foothills, upper shrub-steppe, open forests, meadows,
and roadsides
HOST PLANTS Common Snowberry (Symphoricarpos albus), Shrubby Penstemon
(Penstemon fruticosus), Common Mullein (Verbascum thapsus),
honeysuckle (Lonicera spp.), and Indian paintbrush (Castilleja spp.)
NOTE Caterpillar that adapts to conditions, prolonging or shortening
its development
CONSERVATION STATUS Not evaluated, but common in many locations

ADULT WINGSPAN
2–2⅛ in (50–55 mm)
CATERPILLAR LENGTH

1 ⁄ –1⅜ in (30–35 mm)
EUPHYDRYAS COLON
SNOWBERRY CHECKERSPOT 227
(W. H. EDWARDS, 1881)

Snowberry Checkerspot females lay batches of 50 to 200 eggs on

host plant leaves in June, which hatch into rst instar caterpillars
within two weeks. The first three instars are gregarious,
consuming leaves in messy silk nests, and expanding or moving
nests when the food supply is exhausted. The caterpillars
overwinter in the second or third instar, often in nests on upper
parts of the host plant. They recommence feeding in spring,
but if food is in short supply or of poor quality they will reenter
dormancy. In challenging conditions, caterpillars may pass Actual size
through up to seven instars before pupation.
The Snowberry Checkerspot caterpillar is
Caterpillars of Euphydryas colon likely sequester iridoid alkaloids variably colored but usually some combination
of black, orange, and white. Three large, orange
from host plants, making them unpalatable to some predators. spots are present on each segment, and large,
Their spines also confer protection. There are a number of branching setae impart a spiny appearance.
The black head bears long, white setae.
Euphydryas checkerspot species in western North America, all
with similar caterpillars and life cycles. The adults are a common
sight in mountainous habitats, nectaring on alpine owers.