Page 594 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

MOTH CATERPILLARS

FAMILY Noctuidae
DISTRIBUTION North America, east of the Rockies
HABITAT Deciduous woodlands and forests
HOST PLANTS Woody plants, including maple (Acer spp.), alder (Alnus spp.),
birch (Betula spp.), elm (Ulmus spp.), willow (Salix spp.), and
ash (Fraxinus spp.)
NOTE Caterpillar that can cause a severe rash when roughly handled
CONSERVATION STATUS Not evaluated, but usually common

ADULT WINGSPAN
2–2 ⁄ in (50–65 mm)
CATERPILLAR LENGTH
2–2⅛ in (50–55 mm)
ACRONICTA AMERICANA
AMERICAN DAGGER
592
HARRIS, 1841

American Dagger caterpillars hatch from green eggs laid
singly by the female moth and live solitary lives feeding on the
leaves of their host trees. Early instar caterpillars graze leaves,
skeletonizing irregular patches of lower leaf tissue, while later
instars eat entire leaves. The larvae rest with their head curled to
one side. Prepupal caterpillars wander and excavate a pupation
crypt in soft wood or bark. A tough cocoon is constructed within
the excavation, in which pupation occurs. There is a single
generation of caterpillars in the north of the range, where the
pupae are most likely to overwinter, but two or three in the south.
Although harmless to the touch, roughly handled American
Dagger caterpillars can produce a severe rash.

The larvae appear between July and October, while the adult

The American Dagger caterpillar is large and moths y between April and September. The caterpillars are
densely covered with long, white or pale yellow
setae from which emerge black, diverging tufts frequently attacked by parasitic wasps, which deposit numerous
of black hair on the rst and third abdominal eggs in each larva. After consuming the caterpillar’s insides, the
segments. A single long, black hair tuft is present
on the eighth abdominal segment. wasp larvae pupate in the cadaver, emerging later as adult wasps.

Actual size