Page 227 - 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 to New Mexico

HABITAT Moist mountain meadows, bogs, elds, and canyons
HOST PLANTS Grasses, including Poa spp. and Setaria spp.
NOTE Rarely seen, nocturnally feeding, mountain grass caterpillar
CONSERVATION STATUS Not evaluated, and though usually common may be rare
in parts of its range

ADULT WINGSPAN
1¾–2 in (45–50 mm)
CATERPILLAR LENGTH
1 ⁄ –1⅜ in (30–35 mm)
EREBIA EPIPSODEA
COMMON ALPINE 225

BUTLER, 1868

In June, the female Common Alpine selects an egg-laying site
by walking through grasses, then lays her eggs singly. After
eight to ten days, the caterpillars hatch and feed for 20 to 30 days
before entering dormancy in the third or fourth instar. Feeding Actual size
recommences after overwintering, and the larvae may complete
development, pupate, and produce adults in the summer.
In some locations, overwintering occurs for a second time
before pupation. The caterpillars are solitary, feed nocturnally,
and rest at the base of grasses during the day.

Camouflage appears to be the primary defense of these The Common Alpine caterpillar is pinkish tan
caterpillars, which can be attacked by spiders and predatory with a prominent, middorsal, black stripe. The
less distinct, lateral, white stripes are bordered
mites. To survive overwintering, they require high humidity, below in black. Profuse short, pale setae arise
but the same conditions are detrimental during spring. Adults from tiny, white spots, giving an overall
granulated appearance, and the abdominal tails
visit owers for nectar, and males also imbibe from mud and are short. The setaceous head is greenish tan.

dung. Males emerge before females and patrol circular routes,
while females tend to remain hidden in grass.