Life Cycle of the red
The pale green eggs measure c. 0.8 mm in height
and turn darker in colour during maturation. They are laid singly
the upperside of leaves, usually the terminal leaves of the Common
Hatching takes place in c. 5-10 days in suitable weather.
The adult larva measures up to 36 mm in length and occur in several
The dark form is greyish-black and all the segments have branched spines
of the body colour.
The paler form is greyish-green and all the segments have branched
spines of the body colour.
All have pale-yellow markings on the abdominal segments close to the
spiracles. The head is black.
The earliest larvae occur in June but are commonest in August and
The young larva constructs a tent from a nettle leaf which is folded over
and held together by silk threads,
in which it shelters and emerges to feed. As it feeds and
grows it constructs larger tents until fully grown
when it goes on to pupate when conditions are favourable.
Pupation takes place from July onwards, the pupa forming
inside the tent and suspended from a silk
pad on the roof by means of anal claspers. This stage lasting c.17 days.
The offsprings of the immigrant butterflies arriving in May and June may
contribute to the larger
immigrant numbers arriving in August and September and even into October.
They have a strong and powerful flight with intermittent gliding.
They feed on flower nectar, juices of fermenting fruit and
sap from injured trees.
are able to survive the Irish winters in any state.