Page 636 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

MOTH CATERPILLARS

FAMILY Noctuidae
DISTRIBUTION Southern United States, in California, and from Kentucky and
Maryland in the east, Oklahoma and Texas in the west, south to
the Caribbean, Central America, and South America to Argentina
HABITAT Diverse, including agricultural land, woodlands, grasslands,
and wetlands
HOST PLANTS Wide range of wild and cultivated plants, such as Sweet Potato
(Ipomoea batatas), and even chemically defended plants such
as rattlebox (Crotalaria spp.), greenbrier (Smilax spp.), and
nightshade (Solanum spp.); also, in Florida, recorded on a
semiaquatic plant, Dotted Knotweed (Persicaria punctata)
NOTE Armyworm from a genus of highly destructive crop pests
CONSERVATION STATUS Not evaluated, but common

ADULT WINGSPAN
1 ⁄ in (40 mm)
CATERPILLAR LENGTH
1 ⁄ –2⅜ in (40–60 mm)
SPODOPTERA DOLICHOS
SWEET POTATO ARMYWORM
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(FABRICIUS, 1794)

Sweet Potato Armyworm caterpillars hatch from as many
as 4,000 eggs laid by a single female and feed on host plants
from more than 40 families, illustrating their potential to be an
explosive pest. However, their pest status is minor or negligible
compared to some other species in the genus. The caterpillars are
extensively parasitized by tachinid ies, and, while their eyespots

may scare some predators, their only other defense is to fall to
The Sweet Potato Armyworm caterpillar has the ground when disturbed. The larvae are initially gregarious
a sausage-like appearance, smooth, thick, and but disperse at later instars. They develop from hatching
segmented. It is brown, with black markings
dorsally and a darker spiracular line, although to pupation in around 23 days, with female larvae taking longer
the spiracles may have lighter markings. The
markings on the rst thoracic and last abdominal than males and undergoing six or seven instars. The larvae
segments point anteriorly and posteriorly and pupate in the soil within a silk-lined cell.
are eyelike, an impression accentuated by
additional posterior markings on every segment
and white markings along the subdorsal line.
The genus Spodoptera, which evolved between 5 and 11 million
years ago, includes more than 30 species. A number of species, such
as the Fall Armyworm (S. frugiperda) and the Beet Armyworm
(S. exigua), are highly destructive. Identification of both

adults and larvae in the genus is di cult, and tiny characteristics
may be used, such as the band on the thorax of the S. dolichos
adult, which gave the species another common name,
Banded Armyworm.

Actual size