Life Cycle of the clouded
The tall, spindle-shaped. pale-yellow egg measures c.1.1 mm
in height, turning pink then orange as it matures.
It is laid singly, usually around mid-June, on the upper side of
legume leaves or other food plants. Hatching
takes place in c. 6-10 days provided the weather is suitable.
The adult larva measures up to 33 mm in length. The body is
green and covered with short white hairs.
There is a pale-yellow spiracular line with a series of red and orange
markings either side of the spiracles.
The head is green.
Immigration of the earlier adult butterflies can last from mid-May to
mid-July and the resulting larvae can be
seen anytime between June and August.
Larvae from the second brood and other migratory individuals can result
in the larval period lasting from
anytime between June and October.
After hatching the larva eats its eggshell and then feeds on the leaves of its foodplant.
When fully fed it goes
on to pupate in favourable weather but is easily killed by damp and frost.
The pupa is suspended from a silken pad, spun by the adult larva
on plant stems, by cremasteral hooks and
a fine silk girdle. Butterflies emerge in favourable weather in c.
2-3 weeks but the pupae are easily killed by
damp and frost.
Migratory adults may be seen on the wing from mid-May to mid-June and
again in late July to
These numbers can be increased by early summer immigrants breeding locally and
producing an Irish
generation which emerges from pupation in
September and sometimes survives into late
None survive Irish winters.
Years in which Clouded Yellows are plentiful are called "Edusa
Years" (from its old name Papilio edusa).
About 10% of females have the orange on their wings replaced by light
yellow and are know as f.helice.