Page 488 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

MOTH CATERPILLARS

FAMILY Geometridae
DISTRIBUTION
DIS TRIBUTION Europe and across northern Asia to Korea and Japan
DISTRIBUTION
HABIT
HABITAT T Forests, woodlands, parks, and heathlands
HABITAT
A
HOST PLANTS
T PLANT
HOST PLANTS S Birch (Betula spp.)
HOS
NOTE
NOTE Caterpillar that is active at night and rarely observed
TE
NO
T
CONSERV
CONSERVATION STATUS
TION S
A
TUS
A
CONSERVATION STATUS Not evaluated, but locally endangered
ADULT WINGSPAN
1 ⁄ –1 ⁄ in (30–40 mm)
CATERPILLAR LENGTH
1 in (25 mm)
ARCHIEARIS PARTHENIAS
ORANGE UNDERWING
486
(LINNAEUS, 1761)
Orange Underwing caterpillars hatch from eggs laid in small
groups on birch twigs, usually in the angle between a twig and
a bud. The larvae hatch at night, which is also the time they
feed—initially on catkins before moving on to the leaves.
During the day, the caterpillars shelter in a silk web or leaf tent.
Actual size
They move to the ground to pupate in leaf litter or under moss
and overwinter there.

Archiearis parthenias adults, produced within a single generation,
are active on bright, sunny spring days, when they can be seen
The Orange Underwing caterpillar is dark flying around the tops of birch trees. The moths are spotted
green with several white lines running the mostly in April and May, although they can appear as early
length of the body, which is scattered in black
dots and covered in sparse hairs. A distinctive, as February. The species is endangered in some parts of its
lateral, white stripe runs below the spiracles.
The head and legs are paler in color. range due to the loss of birch woodland and the expansion
of commercial conifer plantations. Many of the colonies are
small and fragmented.