Page 192 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

BUTTERFLY CATERPILLARS

FAMILY Nymphalidae
DISTRIBUTION Western United States, from Washington State south to
Arizona and southern California
HABITAT Shrub-steppe, canyons, hillsides, and mountain meadows
HOST PLANTS Violet (Viola spp.)
NOTE Secretive, spiny caterpillar that feeds nocturnally on
desert violets
CONSERVATION STATUS Not evaluated, but common

ADULT WINGSPAN
2⅜–2¾ in (60–70 mm)
CATERPILLAR LENGTH
1⅜–1 ⁄ in (35–40 mm)
ARGYNNIS CORONIS
CORONIS FRITILLARY
190
(BEHR, 1864)

Coronis Fritillary caterpillars hatch from eggs laid singly during
fall in shrub-steppe among patches of dried-up violets. Initially
they do not feed but, instead, they hide under rocks and plant
debris for overwintering. The larvae begin feeding in spring as
the violets develop new growth. The caterpillars are rarely seen
as they are nocturnal, feeding by night and hiding under rocks

by day. Young larvae prefer to feed on violet owers and young
leaves at first, moving to older leaves later. They have three
modes of defense—concealment, their spines, and an eversible
ventral gland that emits a bad odor.

Actual size
Pupation occurs close to the ground within a few leaves silked
together to provide a tent. Adults migrate up to 100 miles
(160 km), leaving the hot, dry shrub-steppe to spend summer
in cooler, ower-rich, high-elevation meadows. They return

to the shrub-steppe for egg-laying in early fall. It is unknown
how females find and recognize areas of dried-up violets
for egg-laying but it is assumed that they are able, somehow,
to “smell” the host plants.

The Coronis Fritillary caterpillar is dark gray
to black, mottled with white spots and patches,
especially laterally. There is a prominent pair
of middorsal, white stripes, and the black
dorsal spines have orange bases. A row of
lateral spines is orange. The head is black
with very few or no orange markings.