Life
Cycle of the Common Blue
Ovum:
The small white disc shaped eggs, measuring up to 0.6 mm in diameter, are
laid singly on the young terminal
leaflets of Bird's-foot-trefoil and other leguminous food plants,
and hatch in c.9 days.
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©
DHardiman 2001 |
Larva:
The fairly stout larva measures up to 13 mm in length, tapers towards
the extremities and is flattened
towards the sides. The body is green with a darker green
mediodorsal line and whitish lateral stripe below
the level of the white spiracles. The small glossy head can
retract into the body. The setae are light brown
dorsally and white laterally. On the upper surface of the 10th
segment there is a honey gland.
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©
DHardiman 2001 |
The larva feeds on its food plant by day and the first generation is
fully grown in about 6 weeks and
goes on to pupate. But those of the second generation overwinter ,
probably in their third instar, about
late Septrmber/early October. They hibernate low down on the stem
of the food plant or on leaf litter.
It is often seen tended by ants who are attracted by its honey-like
secretions, a feature seen in other members
of the Lycaenidae family. Feeding is resumed late March or early
April of the following spring.
Pupa:
Pupation of the overwintering larva occurs about April but later in
summer for the
following generation(s).
This occurs at the base of the food plant or sometimes on its lower stem under a few
strands of silk.
Some are buried by ants and it may occasionally be seen inside an ant's
nest under a stone.
The pupal stage lasts c. 14 days.
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©
DHardiman 2001 |
Adult:
The adult is on the wing by mid-May to early
July and again in late July to early September and
later for further generations.
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Common Blue
mating ©
DHardiman 2004 |
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