8 Amazing Facts About the Atlas Moth

The atlas moth is one of the largest moth species in the world. Its massive wingspan is wider than a human hand. Found in tropical and forest habitats throughout Asia, the atlas moth has reddish-brown wings with triangular patterns outlined in black. This extraordinary moth also lacks the ability to eat and has an incredibly short lifespan.

As a caterpillar, the atlas moth is also quite impressive. The larvae feed constantly, storing up for the pupal and adult stages. From their ability to mimic a snake to their impressive silk cocoons, discover the most fascinating facts about the atlas moth.

1. Atlas Moths Are Massive

One of the largest moth species in the world, the atlas moth (Attacus atlas) is found throughout Asia and is widespread in China, Bangladesh, Cambodia, Hong Kong, India, Laos, Malaysia, Nepal, and Taiwan. With a wingspan of up to 12 inches and a total surface area of as much as 62 square inches, it is second only to the white witch moth in wingspan and the Hercules moth in total wing surface area.

2. They Are Huge as Caterpillars

Atlas moths begin their lives as good-sized caterpillars. Two weeks after hatching, the atlas moth caterpillar feeds ravenously, first on its eggshell and then on its favorite leaves from citrus, guava, cinnamon, and Jamaican cherry trees, taking in enough food to last for its pupa and adult moth stages.

Those caterpillars that live in captivity (such as in a butterfly conservatory) may be kept in a special feeding area to feast on privet, a type of flowering shrub, so as not to decimate other plants. Luke Brown, manager of the British Natural History Museum's butterfly house, said, "We don't let them roam free in the exhibition because they eat so much. This allows them to build up fat reserves for the adult to live off. If we didn't monitor their eating, we would have no plants left in the butterfly house, so we keep them in their own feeding area while they are growing."

The caterpillars can reach up to four and a half inches in length before they pupate. They spin a cocoon filled with bits of leaves and emerge after about a month as an enormous atlas moth.

3. The Caterpillars Have a Great Defense

Atlas moth caterpillars are also impressive in their defense strategies. They have a threatening appearance—the caterpillars are a bluish-green color with spiny protuberances and a white waxy coating. The larvae have a secretion that they can spray a distance of nearly 12 inches that has a powerful odor and can be used against predators like ants and lizards. They can also spray an "irritant secretion" into the eyes of threatening birds from up to 20 inches away.

4. They Don't Eat as Adults

Adult atlas moths don't eat because they don't even have fully formed mouths. Their proboscis is tiny and non-functioning. Though it seems extraordinary, this is fairly common in moths. They live on the reserves they store as caterpillars. Once the atlas moth emerges from the cocoon as an adult, its sole purpose is to find a mate. The moth doesn’t travel far from its cocoon, saving all of its energy for reproduction.

5. Their Wingtips Are a Warning

The atlas moth has what appears to be a built-in method for scaring off predators; its wingtips look just like cobra snake heads. When the atlas moth is threatened, it slowly moves its wings to mimic a snake to ward off potential attackers. Since cobras are found in the same areas as the atlas moth, and because its main predators, birds and lizards, are visual hunters, it seems likely that this wing marking is an adaptation for survival.

If the snake markings are not sufficient to keep predators at bay, the atlas moth also has the appearance of false eyes on its wings. These eyes can startle predators, but also distract them from more vulnerable parts of the moth's body, possibly sparing it from death if attacked.

6. They Mate Efficiently

The primary purpose of the atlas moth is to find a mate and reproduce. Because they’re short on time, they accomplish this quite efficiently, sticking close to home for mating purposes. In order to conserve energy, they rest during the day and do most of their movement at night. The female moth releases a pheromone that is picked up by the male’s chemoreceptors. Once they mate (a process that can last up to 24 hours), females lay as many as 150 eggs, and the moth dies soon after.

7. They Only Live for a Couple of Weeks

The beautiful atlas moth only lives for about one to two weeks. Born without the ability to eat, the moths are unable to last any longer on the food reserves they store as caterpillars. With only enough time to mate and lay their eggs, these gentle giants preserve their energy, remaining as still as possible in their race against time.

8. Their Silk Cocoons Are Used to Make Products

Once they reach about four and a half inches in size, atlas moth caterpillars form silken cocoons. This stage lasts about four weeks, after which the adult breaks out of the cocoon. The cocoon is made of strands of silk called fagara. The color of the silk ranges from tan to brown depending on the plants eaten by the caterpillar. In some locations, the cocoons are collected and used as small purses. Other products made from their silk include ties, scarves, and shirts.