Page 366 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

MOTH CATERPILLARS

FAMILY Saturniidae
DISTRIBUTION North America, from Arizona, Colorado, New Mexico,
and west Texas to Mexico
HABITAT Oak woodlands

HOST PLANTS Co ee Berry (Rhamnus californica) and willow (Salix spp.)
NOTE Caterpillar of a species that is distinctive within its genus
CONSERVATION STATUS Not evaluated, but common within its range

ADULT WINGSPAN
2 ⁄ –3 ⁄ in (74–94 mm)
CATERPILLAR LENGTH
2 ⁄ –2 ⁄ in (55–65 mm) AGAPEMA HOMOGENA
ROCKY MOUNTAIN
AGAPEMA
364
DYAR, 1908

The Rocky Mountain Agapema caterpillar hatches from a cluster
of 45 to160 ivory-colored, oval eggs in the summer. Initially, it is
all black with white hairs but in the second and remaining instars
it becomes black and yellow. It is gregarious until the fourth and

nal instar, when it becomes solitary. The mature caterpillar
leaves the host plant and spins a u y, tan-colored cocoon in

a crevice of rock or tree trunk in the fall, and the pupa spends
the winter often covered by snow.

There are seven species of Agapema in the western United States
and Mexico. All are similar as caterpillars and adults, except the
Rocky Mountain Agapema, which is larger, more attractive, and
lives in a forested environment at a higher altitude. The other six
are desert species. Many of the larvae are parasitized by tachinid
flies, which lay their eggs on the leaves that the caterpillars
feed on, eventually killing a larva after it has made a cocoon.
Actual size

The Rocky Mountain Agapema caterpillar
is black, overlaid with a bold, yellow pattern
repeated on each segment. There are many
short, white hairs and fewer very long ones
on the body and medium-long, curved ones
on the abdominal legs and prolegs. The head
and legs are black, and there is a white patch
on each abdominal leg.