Page 380 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

MOTH CATERPILLARS

FAMILY Saturniidae
DISTRIBUTION Eastern and central United States, west to the Rocky Mountains
HABITAT Forests
HOST PLANTS Many, including Black Cherry (Prunus serotina) and willow
(Salix spp.)
NOTE Caterpillar with spines that can deliver a painful sting
CONSERVATION STATUS Not evaluated, but common

ADULT WINGSPAN
2–4 in (50–100 mm)
CATERPILLAR LENGTH
2⅜–4 in (60–100 mm)
AUTOMERIS IO
IO MOTH
378
(FABRICIUS, 1775)

Io Moth caterpillars feed in groups initially; the group size is
usually determined by the size of the egg cluster from which
they hatch. Females are capable of laying about 300 eggs, but in
nature they rarely lay more than 20 at a time. The caterpillars
The Io Moth caterpillar is green with are brown at first, then become green, with orange, yellow,
a brown abdomen and white-and-red and white stripes that add to their aposematic coloration. They
(or white-and-orange) longitudinal stripes
on its side. There are rows of projections are well defended against predators as they have spines that,
on every segment, which contain glands
that secrete poison through numerous if touched, will cause a beelike sting, and may cause a severe
branching, stinging spines. reaction. The caterpillar takes two to three months to develop.

Toward the end of their development, the caterpillars become
solitary and build a thin, brown cocoon among leaves. The
adults are sexually dimorphic, with yellow (sometimes orange
or pink) forewings in males and brown in females. When the
moth is at rest, the forewings cover the eyespot on the hindwing
that distinguishes the species. The range of the Io Moth is more
northerly than other member species of the large, mostly
Neotropical Automeris genus.

Actual size