Butterflies of the
Long-tailed Blue / Pea
Family - LYCAENIDAE
Tribe - POLYOMMATINI
Chilapata, West Bengal, India
© Adrian Hoskins
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 Malaysia, Indonesia and Australia. It
reached New Zealand in 1965, and Hawaii in 1882. It has not yet
reached the Americas, although it is likely to do so within a few
years, most probably as a result of being accidentally introduced
with an imported plant.
In the Oriental
region boeticus is very widespread and
common, largely due to the use of one of its larval foodplants
Crotalaria as a cover plant in rubber
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.
This highly adaptable species is
found in many different types of environment including coastal
habitats, open grasslands, riverbanks, plantations ( e.g. oil palm,
tea, eucalyptus, rubber ), parks, gardens, temperate forests and
along roadsides. It occurs at all elevations up to about 1800m.
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 including Alhagi,
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
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.
Males also visit damp ground to imbibe mineralised moisture, usually
aggregating with other Polyommatine species.
The thin 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 feeding it often walks about in
tight circles, thus a predator is never quite sure which direction it
is facing. It also jiggles its hindwings, causing the tails to wiggle
like antennae. This reinforces the back-to-front illusion, and tricks
attacking birds into aiming at the tail instead of the head or body,
enabling the butterfly to escape relatively unharmed, while leaving
the bird with nothing but a piece of detached wing in its beaks.
Overnight or in dull weather the butterflies roost on dead flowerheads
or at the top of tall stems, adopting a head-downwards posture.
male, Yoksam, West Sikkim, India ©