Attacus atlas (atlas moth)

Key characteristics

The adult atlas moth has very broad wings and a large wing surface area compared with most moths. Wingspan can reach extraordinary dimensions among moths, and wing coloration blends browns, reds and cream bands with translucent window-like spots. Adult moths have reduced or non-functional mouthparts and do not feed; they survive on fat reserves accumulated as caterpillars, usually for only one to two weeks while they mate and lay eggs. More on their range is described at distribution.

Life cycle and behavior

1. Egg: tiny, laid on host-plant leaves.
2. Larva (caterpillar): large, voracious leaf-eating stage that grows through several molts; often green with tubercles and a waxy surface.
3. Pupa: enclosed within a dense cocoon of silk where metamorphosis occurs.
4. Adult: winged moth with limited lifespan and a primary focus on reproduction.

The cocoon is a tough silken structure. The silk produced by atlas moth caterpillars is coarse and difficult to reel into continuous filament silk, so it is generally spun rather than reeled for local textile uses.

Significance and distinctions

Attacus atlas is frequently cited in lists of the world's largest moths, alongside a few other giant species. Its dramatic wing shape and cryptic markings make it a popular subject in natural history and insect collections. Because adults do not feed, conservation of the species depends on preserving larval host plants and suitable habitat. For technical details on wing measurements and comparisons see wing data.

Although not typically listed as critically endangered, atlas moth populations are sensitive to deforestation, habitat fragmentation, and collection in some localities. They remain an important example of how life-history traits — such as a short adult stage and a long larval feeding period — shape ecology and human interest in large moth species.