Page 226 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

BUTTERFLY CATERPILLARS

FAMILY Nymphalidae
DISTRIBUTION Mountainous regions of northwest Europe, across central Europe
to the Urals, southern Siberia, Mongolia, and northeastern China
HABITAT Forest margins and clearings, and damp grasslands up to
7,875 ft (2,400 m) elevation
HOST PLANTS Grasses, particularly Agrostis spp., Dactylis spp., and Poa spp.
NOTE Striped, brown caterpillar of upland grassland and forest margins
CONSERVATION STATUS Not evaluated

ADULT WINGSPAN
1¾ in (45 mm)
CATERPILLAR LENGTH
1 in (25 mm)
EREBIA AETHIOPS
SCOTCH ARGUS
224
(ESPER, 1777)

The female Scotch Argus lays her spherical egg singly on short
grass leaves and seed heads. The caterpillar is slow growing,
often feeding at night and resting near the base of the grass
during the day. If disturbed, it falls to the ground and “plays
Actual size
dead.” The young caterpillar overwinters in leaf litter near the
base of the food plant and becomes active again the following
April. Mature larvae move to the ground to pupate in a loose
cocoon near the base of the food plant, often in moss and lichen.

There is one generation a year, with the adults flying late
The Scotch Argus caterpillar is sluglike in in summer, usually in July and August. Erebia aethiops has
appearance with a large head and tapered experienced a decline in its distribution due to loss of habitat and
body. Many dark brown and pale brown
stripes run along its length, and bands of lack of habitat management, but numbers are increasing again
small, raised tubercles each bear a short hair.
in some parts of its range. In favorable habitats, the species may
exist in colonies of hundreds or even thousands of individuals.