Page 90 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

BUTTERFLY CATERPILLARS

FAMILY Hesperiidae
DISTRIBUTION Western United States, west of the Rockies, from Washington
State to northern Mexico
HABITAT Riverbanks, roadsides, and canyons in arid country
HOST PLANTS Mallows, including Common Mallow (Malva sylvestris),
Cheeseweed (Malva parvi ora), and Hollyhock (Althaea rosea)

NOTE Nocturnal-feeding, nest-building, green caterpillar
CONSERVATION STATUS Not evaluated, but usually common

ADULT WINGSPAN
1¾–2 in (45–50 mm)
CATERPILLAR LENGTH
1–1⅛ in (25–28 mm)
HELIOPETES ERICETORUM
NORTHERN WHITE SKIPPER
88
(BOISDUVAL, 1852)

Northern White Skipper caterpillars hatch from eggs laid singly
during summer on the underside of terminal leaves of the host
plant. Development from egg-laying to pupation takes about
seven weeks, with the pupal period lasting up to four weeks,
even under warm conditions. Early instars hide in the furls of
young terminal leaves of mallows and construct small, folded
leaf nests silked together at the leaf edges. These instars feed
halfway through leaves, creating “window panes,” with round
holes produced later as the larvae mature. Nests become larger as

the caterpillars grow, with pupation taking place in the final nest.

Feeding is mostly nocturnal, and larvae shoot frass away
from themselves to confuse enemies. Predation by pirate bugs

(Anthocoridae) is common, however. The fast-flying, relatively
large skipper adults may undertake seasonal migrations in spring
and fall. The males are often seen sipping moisture from muddy

patches, while females are frequently spotted on flowers.

The Northern White Skipper caterpillar is
variegated pale bluish green and pale yellow.
There are numerous white speckles on the body,
and the many pale setae are long enough to
appear shaggy. The black head is densely
clothed in setae, creating a hoary appearance.
The collar is white with small, brown speckles.
Actual size