Page 140 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

BUTTERFLY CATERPILLARS

FAMILY Riodinidae
DISTRIBUTION Southwestern Canada, western United States, and Mexico

HABITAT Desert canyons, arid flats, banks, and roadsides
HOST PLANTS Buckwheat (Eriogonum spp.)

NOTE Slow-growing caterpillar that becomes a fiery-colored,
fall butterfly

CONSERVATION STATUS Not evaluated, although subspecies Apodemia mormo langei
is critically imperiled

ADULT WINGSPAN
1¼ in (32 mm)
CATERPILLAR LENGTH
1¹∕₁₆ in (27 mm)
APODEMIA MORMO
MORMON METALMARK
138
(FELDER & FELDER, 1859)

In northern parts of its range, the Mormon Metalmark caterpillar
develops very slowly during spring and summer, spending much
time in apparent dormancy. Late instars may make loose silk
nests to rest in. Pupation occurs in late summer, and the butterfly

flies in early fall. The eggs develop embryos but then diapause
and overwinter. Caterpillar survival appears to depend on
Actual size concealment in refugia, but the bright purple and gold coloration
may be aposematic. The caterpillars feed on many buckwheat
species, chewing small holes through the leaves.

Approximately 15 closely related metalmark butterfly species

occur from Canada to Brazil. The seasonality of these species
(including Apodemia mormo) varies according to latitude, with
more southerly species having earlier and longer flight periods.

Young caterpillars—instead of eggs—may overwinter in lower
latitude populations. The subspecies A. mormo langei, which
occurs in the Antioch Dunes of California, is endangered due
to loss of habitat and host plants.

The Mormon Metalmark caterpillar is purple
with bold, paired, black, raised spots dorsally.
Yellow or gold-orange spots occur between the
black spots. Two rows of gold spots are present
laterally, with long, white setae arising. The
intensity of colors and markings varies
geographically. The head is black.