Search by Subject
Search by Institution
Attacus atlas formosanus Villiard, 1969 皇蛾

Tags: insect | moth

  

Attacus atlas formosanus Villiard, 1969 皇蛾

 
 

 

The Atlas moth, Attacus atlas (Linnaeus), is considered as the world largest moth in terms of the total wing surface area which is up to 400 square centimeters. The adult has a wingspan of 20-25 cm or greater, and the females are larger than males in general. Each wing is featured with a scale-free, transparent cell in the middle.  The forewing tip is moderately projecting outward, tapering more in males than in females. The Chinese vernacular names of the species are “snake-head moth” or “emperor moth” in literal English. The former is referring to the shape of the forewing tips which resemble a snake’s head; the latter is referring to the grand size of the moth. It is widely distributed in Southeast Asia from India, Malay Peninsula to southern China and Taiwan and has many described subspecies.
 
Each female has a fecundity of about 200 eggs in average. Several eggs are laid one time on the tree bark or the underside of the leaves. The larvae are polyphagous, feeding on several families of plants such as Bischofia javanica Blume, Glochidion rubrum Blume (Euphorbiaceae), Schefflera octophylla Lour, Harms (Araliaceae), and Ardisia sieboldii Miq. (Myrsinaceae). In addition, Psidium guajava, Damnacanthus angustifolius, Cinnamomum verum, and Syzygium samarangense among several others could be used as substitutes in artificial rearing (Wang, 1994). The larvae bear many fleshy projections along the trunk, but are harmless to human beings.  A mature larva may be up to 11 cm in length. It takes about 70 days from egg to adult, with 9, 40 and 21 days for egg, larval and pupal stages, respectively. Emergence occurs usually around midnight and the adults fly away by the next night. The mating lasts three to ten hours. Females start laying eggs the night after mating (Wang, 1994).
 
The endemic subspecies A. atlas formosanus is the largest moth in Taiwan. It is bivoltine in northern area. The first generation emerges in May and June, and second in August and September. The species overwinters as pupae. In tropical areas, three to four generations can be bred annually. In the 1970s, the Atlas moth was raised in large number in Taiwan for commercial use. The adults were made into specimen decorations and the cocoons were used to make purses. The population gradually returned its natural states after the insect industry declined in the 1980s.
  
 
National Museum of Natural Science (The Digital Museum of Nature & Culture