Butterflies of
Thailand, Malaysia &
Borneo
Oriental Ciliate Blue
Anthene emolus
GODART, 1824
Family - LYCAENIDAE
subfamily -
POLYOMMATINAE
Tribe -
LYCAENESTHINI
introduction
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habitats |
lifecycle |
adult behaviour
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Anthene emolus,
Bukit Tapah, West Malaysia |
Introduction
Although they are tiny and inconspicuous as adult butterflies,
the Ciliate Blues are fascinating as a species, being entirely
dependent on a single species of ant for their survival.
The genus Anthene comprises of
about 95 species, of which 80+ occur in tropical Africa, 5 or 6
in the Oriental region, and 5 in the Australian region. Malaysia
has 3 species - emolus,
lycaenina and
licates, all of which are widely distributed across the
Oriental region.
The various
Anthene species are commonly known
as Ciliate Blues or Hairtails, due to the fact that the fine
cilia or "hairs" around the wing margins are drawn out into
little tails at veins 1b, 2 and 3 on the hindwings. These short
thin tails are normally only apparent on freshly emerged
specimens however, and are lost after a day or two of activity.
Males of most
species, on the upper surface of the wings, are a lustrous deep
purple or indigo blue colour. Females are usually a dull earthy
brown colour but often flushed with blue or purple around the
base of the wings. Many of the species are difficult to tell
apart, and can only be distinguished by studying small
differences in the pattern on the underside of the wings.
Anthene emolus is a common and
widespread species found from south India and Sri Lanka to
Thailand, Malaya, Sumatra, Borneo and Java.
Habitats
The butterfly breeds in disturbed primary and secondary forest
habitats at altitudes between sea level and about 800m. It is
commonly found along roadsides and riverbanks, and is often
found close to habitations.
Lifecycle
The eggs are laid in batches of up to 150 on saplings of
Saraca,
Nephelium, Cassia,
Heynea and other trees and bushes.
After hatching
and eating their egg shells the tiny larvae are abducted by
kerengga ants Oecophylla smaragdina,
a large aggressive species that constructs its nests among
living foliage on trees. The ants carry their captives into
their nests, where they feed on the leaves, and possibly also on
substances regurgitated by the ants.
The ants make
no attempt to attack the caterpillars, presumably because they
are able to placate them by using a chemical deterrent or
possibly by means of an "appeasement song" - research on several
European "Blues" has shown that their caterpillars and pupae are
able to stridulate or "chirp", and that this sound deters ants
from attacking.
Research by
Fiedler & Maschwitz has shown that the young 1st instar
emolus caterpillars are unable to
survive outside the ant nests, and will not feed on leaves
outside the nest. This could be due to the warm humid
microclimate within the ant nest, or due to a substance produced
by the ants which softens the leaves and makes it easier for the
caterpillars to digest them. Even odder is the fact that after
the caterpillars moult to the 2nd instar, the ants then remove
them from their nests, and carefully transport them to young
sprigs of the foodplant some distance away.
A few days
later when the caterpillars reach their 3rd instar they develop
honey-producing glands on their backs, and they are constantly
attended by the ants, which "milk" them to drink the sugary
secretion. The relationship is not truly symbiotic, because
while the Anthene caterpillars
cannot survive without the ants, the ants are able to obtain
their "honey" from other sources.
The chrysalis
is usually formed some distance from the ant nest - any
butterfly unlucky enough to find itself emerging near the nest
is instantly attacked, torn into pieces, and carried to the ant
nest for consumption.
Adult behaviour
Males are most
commonly seen when aggregating with other Lycaenidae to imbibe
mineralised moisture from river sandbanks, damp roads, boulders
and other sources of sodium. When feeding they always hold their
wings erect, but in cloudy or cool weather they will often bask
on foliage with their wings held half open.
Females are
less conspicuous but can sometimes be seen nectaring at
Lantana flowers.
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