Butterflies of the
Thailand, Malaysia &
Borneo
Tawny Coster
Acraea
violae
FABRICIUS, 1793
Family - NYMPHALIDAE
subfamily -
HELICONIINAE
Tribe - ACRAEINI
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Acraea violae
© Fiona Le maitre |
Introduction
The Heliconiinae comprises of 3 tribes -
Acraeini, Argynnini, and Heliconiini.
The
Acraeini includes the South American genera Abananote,
Altinote and
Actinote; the Oriental / Australian
Cethosia; and Acraea which
includes 220 African species, one Australian species
andromacha, and 2 in the Oriental
region, i.e. issoria and
violae.
All
Acraea species have elongate forewings and rounded hindwings. The wings
are thinly scaled to the extent that in many species they are semi-transparent.
The scales tend to get rubbed off very easily so that insects more than 4 or 5
days old have a distinctly glassy or greasy appearance. The majority of species
are predominantly brownish or greyish in ground colour, and are marked with
bands or patches of red or orange. The basal area of the underside hindwings of most
species is marked with a pattern of small black spots.
Acraea
violae ( incorrectly referred to as A. terpsicore
in some works ) is found in India, Sri Lanka, Bangladesh, Burma and Thailand.
Habitats
This is a relatively common species occurring primarily at low altitudes on scrubby
grasslands, dry open woodlands, beach hinterlands and flowery gardens. It has
however been recorded as high as 2000m in the Western Ghats of India. The
butterfly is seen in the highest numbers in the monsoon seasons, and is quite
scarce at the peak of the dry season.
Lifecycle
The eggs are yellowish,
and laid carefully spaced, in neat batches on the underside of leaves of the
foodplants.
The fully grown larvae
are a dark, glossy reddish-brown colour, except for the thoracic segments which
are whitish. The thorax and abdomen are equipped with multi-branched black
spines along the back and sides.
The pupa is attached
horizontally by the cremaster to a stem. It is whitish, streaked with black on
the wing cases. There are black stripes along the back and sides, and within the
stripes is a series of small yellowish spots.
The larval foodplants
include various genera in the Loganiaceae, Cucurbitaceae and Passifloraceae.
These plants contain toxins that are sequestered by the larvae and inherited by
the adult insects. The toxicity of the adults, in conjunction with their orange
aposematic colouration, affords them with a high degree of protection against
insectivorous birds.
Adult behaviour
This is a colony-forming species.
Even in marginal habitats it is uncommon to see less than half a
dozen flying together, while prime habitats often contain
hundreds. On hot sunny days in April I have often seen swarms of
these butterflies flying in savannah / woodland mosaics in Sri
Lanka.
Both sexes nectar avidly at
Tridax, Tagetes,
Lantana and other wild or cultivated
flowers. They usually hold their wings erect while feeding, but
often pause to bask on flowers or vegetation with their wings
outspread, with the forewings half masking the hindwings. The
butterflies are normally active, nervous, and difficult to
approach. The flight is weak and fluttery, but persistent.
In cloudy weather they roost openly
on woody stems or on grass-heads.
Acraea violae,
Mumbai, India
© Dr Anand
Narkevar
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