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Butterflies of
Europe
Long-tailed Blue
Lampides boeticus
LINNAEUS, 1767
Family - LYCAENIDAE
subfamily -
POLYOMMATINAE
introduction
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habitats |
lifecycle |
adult behaviour
Lampides boeticus France. Photo
courtesy Graham Thompson / Massif Nature Holidays
Introduction
The Long-tailed Blue, or
Pea Blue as it is often called, is the sole member of the genus
Lampides. Despite its small size and apparent
fragility it is strongly migratory, able to cross seas, oceans and low mountain
ranges with relative ease. It is one of the commonest and most widespread
species in the Old World, breeding in southern Europe, almost throughout Africa,
and across southern Asia to Indonesia and Australia, and reached New Zealand in
1965.
The butterfly
reached Hawaii in 1882 but has not yet reached the Americas, although it will
almost certainly manage to do so within a few years, probably as a result of
being accidentally introduced with an imported plant.
Lampides
boeticus is widespread and common in southern
Europe where it produces several over-lapping broods. It occasionally reaches
Britain, e.g. in September 2003 when it bred at Ranmore Common in Surrey.
On the upperside males are pale
blue with narrow dark borders. Females are dark earthy brown, with a slight
flush of pale blue scales at the base of the wings. The pattern on the underside
is unique, so this species is unlikely to be confused with any other.
Habitats
In Europe the butterfly is found mainly in hot,
dry flowery places, including waste ground and cultivated areas, always at low
altitudes. It is commonest in the Mediterranean area, but breeds regularly as
far north as central France and Germany. On the very rare occasions when it
reaches Britain it is usually found on south-facing hillsides or coastal
grasslands.
Lifecycle
The eggs are
china-white and covered with a network of reticulations. They are laid on the
flowers, sepals and flower stalks of herbs and bushes in the family Fabaceae. In
Europe these include Colutea,
Helianthemum, Lathyrus,
Pisum, Phaseolus and
Ulex.
The larvae when fully grown are cylindrical, and occur in several colour forms
including dark green, yellowish green, and pearly white. All forms have a brown
dorsal stripe, reddish lateral streaks and a brown head. The larva has a honey
gland on the 7th abdominal segment which attracts certain ant species which milk
it for the secretion. The presence of the ants is undoubtedly beneficial in
providing a degree of protection against parasitoid wasps and flies. The larva
is cannibalistic at all stages of its life, with the result that only one larva
survives on each plant.
The smooth rounded chrysalis is creamy or pale brown, with a dark dorsal line.
It is usually formed at ground level, attached to a dead leaf.
Adult behaviour
The migratory
nature of the butterfly means that adults can be seen singly almost anywhere,
but normally in the areas where it breeds several can be seen flying together
around leguminous herbs and bushes. Both sexes nectar at a wide variety
of wild and cultivated flowers.
The antennae-like "tails" on the hindwings, together with the orange, silver and
black "eyespot" at the tornus act together to create the impression of a false
head, and divert the attention of birds away from the body. When the butterfly
first settles it immediately turns around, and when it is feeding it often walks
about in tight circles, thus a predator is never quite sure which direction it
is facing. It also oscillates its hindwings causing the tails to wiggle like
antennae. This reinforces the back-to-front illusion, and probably causes
attacking birds to aim at the tail instead of the head of the butterfly,
enabling it to escape relatively unharmed, leaving the bird with nothing but a
piece of detached wing in its beaks.
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