Butterflies of Europe
Family - LYCAENIDAE
© Graham Thompson
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.
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
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.
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
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
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
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.