Butterflies of
Thailand, Malaysia &
Borneo
Common Tiger
Danaus genutia
CRAMER, 1779
Family - NYMPHALIDAE
subfamily -
DANAINAE
Tribe - DANAINI
introduction
|
habitats |
lifecycle |
adult behaviour
Danaus genutia
Introduction
The
subfamily Danainae, which includes the Monarchs & Tigers, Nymphs and Crows,
comprises of about 190 species worldwide.
The
Monarchs and Tigers belong to the genus
Danaus.
They are all large butterflies, characterised by having orange wings with black
veins, a white subapical band, and a double row of white spots around the
margins of the hindwings.
All
butterflies in this subfamily are thought to be toxic or distasteful to avian
predators, their bodies containing toxins derived from the larval foodplants,
and often supplemented by further toxins derived from adult food sources.
The
bright colours of the butterflies "advertise" their poisonous qualities
to birds, in much the same way that the bands of yellow and black of wasps
advertise the fact that they can sting. Consequently any bird that suffers the
unpleasant experience of eating a
Danaus
is unlikely to attack any similarly coloured butterfly. Effectively, a few
individuals are sacrificed for the good of the species as a whole.
There are 4 Danaus
species found in Malaysia -
genutia, chrysippus, melanippus
and affinis,
the main differences between them being in the intensity of the black markings,
and in the extent of the white markings on the hindwings.
Danaus
genutia occurs in
Sri Lanka, India, Burma, Thailand, China, Malaysia, Borneo, Sumatra, Java, New
Guinea and the north-eastern region of Australia.
Habitats
This is a lowland species occurring in disturbed forest edge habitats at
elevations between sea level and about 500m.
Lifecycle
The eggs are laid singly
on the leaves of Graphistemma, Stephanotis, Asclepias,
Cynanchum, Metaplexis,
Ceropegia,
Gymnema, Marsdenia,
Pergularia and
Tylophora.
The caterpillar is black,
marked dorsally with pairs of narrow white transverse dorsal bands, and rows of
yellow spots. Below the spiracles there is a broad white broken band, in-filled
with more yellow spots. Long black filaments
with conical maroon bases project from the 2nd, 8th and 11th segments. These may possibly
be used to
disseminate pheromones, and may function to ward off predators or parasitoids.
The
chrysalis is plump, rounded, smooth, and pale green in colour, marked with black
dots and flecks of gold and silver. It is suspended by the cremaster from a
stem, away from the foodplant.
Adult behaviour
The butterflies are usually encountered singly or in two's and
three's.
They have a slow undulating flight, with fairly shallow wing
beats, and patrol flowery areas, circling about around the tops of
flowering bushes. Both sexes alight periodically to nectar at
flowers, and usually keep their wings held half open or
closed while feeding.
Late in the afternoon, particularly if it becomes cloudy, they
commonly bask with wings outspread on bushes or on dry twigs.
Cloud cover or lowering temperatures cause them to close their
wings, and they then adjust their position to
hang suspended from the twigs overnight. Sometimes groups of half
a dozen or more can be found clustered together at dusk on twigs
or branches.
Danaus genutia,
female
|
