The
Atlas moth is a large
saturniidThe Saturniidae, commonly known as saturniids, are among the largest and most spectacular of the moths. They form a family of Lepidoptera, with an estimated 1,300 to 1,500 described species worldwide...
moth found in the tropical and subtropical forests of
Southeast AsiaSoutheast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
, and common across the
Malay archipelagoThe Malay Archipelago refers to the archipelago between mainland Southeastern Asia and Australia. The name was derived from the anachronistic concept of a Malay race....
.
Atlas moths are considered the largest moths in the world in terms of total wing surface area [upwards of c. 400 cm² (62 sq in)]. Their wingspans are also amongst the largest, from 25–30 cm (10–12 in). Females are appreciably larger and heavier.
Atlas moths are said to be named after either the
TitanIn Greek mythology, Atlas was the primordial Titan who supported the heavens. Although associated with various places, he became commonly identified with the Atlas Mountains in north-west Africa...
of
Greek mythologyGreek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...
, or their map-like wing patterns. In
Hong KongHong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...
the Cantonese name translates as "snake's head moth", referring to apical extension of the forewing, which bears a passing resemblance to a snake's head.
The largest
lepidopteraLepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...
n in terms of wingspan is thought to be the White Witch,
Thysania agrippina. A record specimen of
Attacus atlas from Java measured 262 mm, while
Thysania are claimed to be about 270–280 mm (11 in). Based on some spread specimens and angle of wing, actual measurements of around 289 mm have been estimated.
In
IndiaIndia , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, Atlas moths are cultivated for their
silkSilk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...
in a non-commercial capacity; unlike that produced by the related Silkworm moth (
Bombyx mori), Atlas moth silk is secreted as broken strands. This brown, wool-like silk is thought to have greater durability and is known as
fagara. Atlas moth cocoons have been employed as purses in
TaiwanTaiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
.
Description
Atlas moths are predominantly tawny to maroon in colour with roughly triangular, diaphanous "eyes" on both forewing and hindwing, bordered in black. The purpose of these dramatic, gossamer portals is not clear, but they are thought to play a role in predator avoidance. Their bodies are hairy and disproportionately small compared to their wings. Patterns and colouration vary among the many described
subspeciesSubspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
. Male Atlas moths are distinguished from females by their smaller size, more tapered wings, and larger, bushier
antennaAntennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
e.
Neither sex possess fully formed mouthparts and therefore do not feed; throughout their 1–2-week adult life they survive entirely on larval fat reserves that they build up while they are caterpillars.
Life cycle
| Holometabolism |
 |
 |
|
 |
| Eggs |
Caterpillar |
Pupa |
Imago emerging from Pupa |
Attraction
Females are sexually passive, releasing powerful
pheromoneA pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual...
s which males detect and home in on with the help of chemoreceptors located on their large feathery antennae. Males may thus be attracted from several kilometres downwind. Atlas moths are unsteady fliers, and the female does not stray far from the location of her discarded chrysalis: she seeks a perch where the air currents will best carry her pheromones.
Larva
Once mated, the female lays a number of spherical eggs 2.5 mm in diameter on the undersides of leaves. Dusty-green
caterpillarCaterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...
s hatch after about two weeks and feed voraciously on the foliage of certain
citrusCitrus is a common term and genus of flowering plants in the rue family, Rutaceae. Citrus is believed to have originated in the part of Southeast Asia bordered by Northeastern India, Myanmar and the Yunnan province of China...
and other
evergreenIn botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
trees. The caterpillars are adorned with fleshy spines along their backs which are covered in a waxy white substance.
Pupa
After reaching a length of about 115 millimetres (4.5 in), the caterpillars
pupaA pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
te within papery cocoon interwoven into desiccated leaves. The adult moths emerge after about four weeks.
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