Moths of Thailand,
Malaysia & Borneo
Giant Atlas moth
Attacus atlas
LINNAEUS, 1758
Superfamily - BOMBYCOIDEA
Family - SATURNIIDAE
subfamily -
SATURNIINAE
Tribe -
Attacus
atlas, Singapore
©
Gan
Cheong Weei
Introduction
The
Giant Atlas is generally recognised as being the largest moth in the
world,
having a wing area of about 400 sq cms ( 65 sq inches ). It can
measure up to 30 cms across the wings, but is beaten in terms of
sheer wingspan by a South American moth
Thysania agrippina which can measure up to 32cms across the
wings, although it has a significantly smaller wing area than
Attacus atlas.
There
are 3 Attacus species -
wardi from Australia,
aurantiacus from Papua New Guinea, and
atlas which is found as various subspecies from India and Sri Lanka
eastward to China and across the islands of south-east Asia to Java.
The
Himalayan species edwardsii and the
Malaysian species staudingeri were
formerly included in Attacus but are
now placed in the genus Archaeoattacus.
Habitats
This
species is found
in primary and disturbed tropical rainforest habitats at altitudes
between sea level and about 1500m.
Lifecycle
The plump larvae of the
Giant Atlas moth are huge, growing to almost 5" / 120cm. They feed
on a variety of plants including Annona
( Annonaceae ) Citrus ( Rutaceae ),
Nephelium (
Sapindaceae ),
Cinnamomum (
Lauraceae ) and
Guava ( Myrtaceae ). They often move from one plant species
to another in the course of their development.
Attacus
atlas, fully
grown larva, Singapore
©
Gan
Cheong Weei
Adult behaviour
Despite their huge size and bright colours Atlas
moths are remarkably difficult to find in the wild. The disruptive
pattern breaks up the moth's outline into irregular shapes which
blend well amongst a mix of living and dead foliage. If disturbed
from rest Attacus atlas employs an
unusual form of defence - it simply drops to the ground and slowly
fans the wings. As the wings move, the "snake's head" lobe at the
apex of the forewing oscillates. This is a threat gesture which
deters predators who "see" a snake instead of a moth.
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