Page 194 - 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 Alaska and Manitoba
to Arizona and Colorado
HABITAT Moist alpine and subalpine meadows, watercourses,
and roadsides
HOST PLANTS Violet (Viola spp.)
NOTE Variably colored, nocturnal, spiny caterpillar that is
associated with violets
CONSERVATION STATUS Not evaluated, but common

ADULT WINGSPAN
1¾–2 in (44–50 mm)
CATERPILLAR LENGTH

1 ⁄ –1⅜ in (30–35 mm)
ARGYNNIS MORMONIA
MORMON FRITILLARY
192
(BOISDUVAL, 1869)

Female Mormon Fritillaries crawl on the ground seeking out
suitable oviposition sites among violets, where they lay their eggs
singly. The eggs hatch after ten days, and rst instar caterpillars

seek refuge under leaves and rocks for overwintering. For
optimum survival they require humid conditions. In spring,
the larvae start feeding on violets as plant growth commences.
The caterpillar’s defense is based on spines, chemical protection
from the bad odor produced by a ventral “neck” gland, and
concealment. The coloration and markings of the larvae are

in uenced by geography and elevation.

Development to pupation takes about two months. Mature
caterpillars silk leaves together as “pupation tents,” and pupation
occurs close to the ground; pre-pupae that fall to the ground are
able to pupate successfully. Adults, produced after a further two

or three weeks, y from June to September. Dispersal of adults is

limited, and males patrol for females. Both sexes feed on ower
nectar, but males will also feed on animal scat, mud, and carrion.

The Mormon Fritillary caterpillar is typically
dark brown to black, with orangey-white spines
and a dorsal, orangey-white stripe bisected by
a dark line. Lateral pale markings are limited.
The black head is covered dorsally with brown
Actual size
markings, dotted with black. Some forms are
almost jet black with orange spines.