Page 80 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

BUTTERFLY CATERPILLARS

FAMILY Hesperiidae
DISTRIBUTION Across much of northern North America and northern
Eurasia, including Japan
HABITAT Forest openings, mountain meadows, stream banks, and
moist lowlands
HOST PLANTS Grasses, including Purple Reedgrass (Calamagrostis
purpurascens), Brome (Bromus spp.), and Reed Canary
Grass (Phalaris arundinaceae)
NOTE Night-feeding grass caterpillar that builds a tubular nest
CONSERVATION STATUS Not evaluated, but vulnerable in parts of its range

ADULT WINGSPAN
¾–1 in (20–25 mm)
CATERPILLAR LENGTH
1–1⅛ in (25–28 mm)
CARTEROCEPHALUS PALAEMON
ARCTIC SKIPPER
78
(PALLAS, 1771)

In North America, the eggs of the Arctic Skipper are laid
singly on grasses in early summer and hatch within seven days.
Development from first to fifth instar takes about six weeks, with

fifth instars feeding slowly and entering dormancy after three

weeks within a rolled grass-blade nest. After overwintering, the
caterpillars leave the nest and pupate on a nearby grass blade.
Protection is based on concealment, nocturnal feeding, and

flinging frass to deter predators. Adults readily nectar on flowers
and live for up to three weeks.

Early caterpillar instars pull together the edges of grass blades,
forming hollow, open-ended, tubular nests and tying them
together with silk crossties. Feeding caterpillars often clip
grass blades, leaving the outer 2–3 in (51–76 mm) tips to fall.
The life history of Carterocephalus palaemon varies in Europe
and Asia. Populations have declined in recent decades, and the
species appears vulnerable to habitat disturbance and climate
change. It disappeared from England—where it was known as
the Chequered Skipper—in 1976.

The Arctic Skipper caterpillar is green with
Actual size
lighter green and indistinct white stripes. There
is a bold, white stripe laterally bordered on both
sides by green. The head is light cinnamon brown
and strongly divided vertically.