Cycle of the Grayling
The white oval shaped egg measuring c.0.8 mm in height changes to
a pale yellow before hatching.
They are laid singly on blades or stems of grass in July and
August and hatch in c.17 days.
The mature larva measures up to 30 mm in length tapering towards
the rear. The body is light ochreous
with a conspicuous deep brown mediodorsal line and dark brown stripes in
the subdorsal region. An ochreous
band extends along the spiracular line. The head is
light brown with dark brown stripes and the small
anal points are brown.
The young larva feeds by night on a wide range of grasses
descending and resting at the base of the plant
by day. After the second moult it moves to the base of the
grasses to overwinter
on or in the
sporadically feeding by day and night during mild weather.
But full activity does not begin until the
spring when it resumes feeding and growth, reaching full
development by early June.
Pupation takes place in June when the larva burrows into the soil
creating a small cell, about 10mm below ground
level, which it lines loosely with silk. It is here the pupa is formed. As it does
not possess cremasteral
hooks, the pupa is unattached within the cell . This stage
lasts c.4 weeks.
The adult emerges in July and is on the wing in July and August.
It is only occassionally seen visiting flowers such as heather, thyme
and other purple flowers to feed.