Family - NYMPHALIDAE
subfamily - DANAINAE
Tribe - DANAINI
Danaus chrysippus, Weligaththa, Sri Lanka ©
The subfamily Danainae, which includes the
Monarchs & Tigers, Nymphs and Crows, comprises of about 190 species
Monarchs and Tigers belong to the genus
Danaus. They are large butterflies,
characterised by their orange wings, which have a black apex, and
white subapical spots. On the males there is a patch of raised
androconial ( pheromone emitting ) scales on the hindwings.
butterflies in this subfamily are thought to be toxic or distasteful
to avian predators. Their bodies contain toxins derived from the
larval foodplants, often supplemented by further toxins derived from
pyrrolizidine alkaloids in adult food sources.
The bright colours of
the butterflies advertise their poisonous qualities
to birds in the same way that the bands of yellow and black of wasps
advertise the fact that they can sting. Any bird that suffers the
unpleasant experience of tasting a Danaus
is unlikely to attack any similarly coloured butterfly, so the
advertising is beneficial to chrysippus
- and to species which mimic it, such as
This form of defence is called Batesian mimicry. It is only
effective because the toxic species far outnumber the non-toxic
species. If the situation was reversed, and most of the butterflies
attacked were palatable, the mimicry would serve no purpose.
is found across the
entire African continent, throughout most of Asia south of the
Himalayas, on most of the islands of the south Pacific, and across
much of Australia.
Danaus chrysippus, Chilapata, West Bengal, India ©
This species occurs in many habitats ranging from deserts to
savannah grasslands, dry deciduous woodlands, humid sub-tropical
forests, gardens, parks and cities at altitudes between sea level
and about 1500m.
foodplants include most genera of Periplocaceae and Asclepiadaceae.
Some species of these plants contain cardenolides ( heart
depressants ) which are sequestered by the larvae and passed on to
the adult butterflies. Other species used by the larvae however do
not contain these cardenolides, consequently some adults are
inherently toxic, while others are harmless and edible. In fact
about 80% of adults are non-toxic at the time of emergence. During
their lifetimes however all adults obtain pyrrolizidine alkaloids
and other toxins which they sequester from various plants.
Danaus chrysippus, male, Kirinda, Sri Lanka ©
The caterpillars of
chrysippus are attacked by the host-specific parasitoid wasp
Apanteles chrysippi which accounts for
about 85% of larval mortality.
butterflies are usually encountered in three's and four's in the wet
season, but can be found in greater numbers during the dry season,
when they often outnumber all other species, especially in savannah /
woodland and thorn scrub habitats.
have a slow undulating flight, with fairly shallow wing beats. Both
sexes patrol flowery areas, alighting periodically to take nectar, or
to imbibe fluid from ergot on the leaves and stems.
overcast weather, or when roosting overnight, they hang suspended from
twigs or grass stems, in sheltered forest edge habitats, sometimes in
groups of half a dozen or more individuals.
Danaus chrysippus, male, Weligaththa, Sri Lanka ©