Animal
Luna moth
The luna moth is a big, pale green moth with long tails on its wings. It flies at night, and the grown-up moth never eats.
The luna moth is a large green moth of the forests of eastern North America. Its long, twisting wing tails may help it escape hungry bats. Grown-up luna moths have no working mouth, so they live only about a week, just long enough to find a mate and lay eggs.
Actias luna is a giant silk moth (family Saturniidae) of eastern North America, with a wingspan of 75 to 105 millimeters, eyespots on all four wings and long hindwing tails that are believed to deflect bats' echolocation. Adults have vestigial mouthparts and do not feed; nearly all of the luna's life is spent as a leaf-eating caterpillar or a pupa.
Photo: No machine-readable author provided. Kugamazog~commonswiki assumed (based on copyright claims)., CC BY-SA 2.5, via Wikimedia Commons
Meet the luna moth
The luna moth is a big moth with pale green wings.
Its back wings end in long, curly tails. Each wing has a round spot. Luna means moon, and its spots look a little like moons.
The University of Florida calls the luna moth perhaps the most beautiful moth in North America. Its wings are pale green and can measure up to about 10 centimeters across, as wide as a grown-up's hand. A dark brown edge runs along the front of each forewing, and each back wing ends in a long, twisting tail.
There is a round eyespot on every wing. The name luna comes from these moon-like spots. Luna moths belong to the giant silk moths, a family of big moths, and luna caterpillars spin silk cocoons.
Actias luna is a member of the Saturniidae, the giant silk moths, a family named for eyespots in some species with concentric rings reminiscent of the planet Saturn. The University of Florida calls it arguably North America's most beautiful moth; it appeared on a first-class US postage stamp in 1987.
Adults have a wingspan of 75 to 105 millimeters, a long tail on each hindwing and eyespots on both forewings and hindwings. It has a long scientific history too: Petiver described it in 1700 as Phalena plumata caudata, a name referring to the tails, making it the first North American saturniid reported in the scientific literature. Linnaeus renamed it luna, after its moon-like spots, in 1758.
Quick facts
- Group
- Invertebrate
- Wingspan
- 7.5 to 10.5 cm
- Lifespan in the wild
- 7 to 10 days
Where it lives
Luna moths live in forests in North America.
They live in the United States and in Canada. At night they fly among the trees.
Luna moths live in leafy forests in eastern North America. In Canada they are found from Nova Scotia to Saskatchewan. In the United States they live in every eastern state, from Maine down to Florida and west to eastern Texas and North Dakota.
In the north, there is just one generation of luna moths each summer. Farther south, there are two or three generations a year. In Louisiana and Florida, you can find adult luna moths in every month of the year.
Usually found in forested areas, the luna moth ranges in southern Canada from Nova Scotia to Saskatchewan, and in the United States through every eastern state from Maine to Florida, west to eastern Texas and eastern North Dakota.
The number of generations follows the climate: univoltine (one generation a year) from Michigan northward, bivoltine through the Ohio Valley and trivoltine farther south, with adults found in every month in Louisiana and Florida. In populations with several broods, spring adults are typically a deeper green with reddish-purple wing margins, while later broods are more yellowish. Southern moths also tend to be smaller.
Continent
Its habitat
Where can you find this animal?
- Lives here naturally · Countries and seas named by a scientific source
- Sightings recorded · Records of wild sightings (GBIF)
Lives here naturally · Countries and seas named by a scientific source
Forests of eastern North America: southern Canada from Nova Scotia to Saskatchewan, and the eastern United States from Maine to Florida, west to eastern Texas and eastern North Dakota.
Places: United States and Canada.
Source: https://ask.ifas.ufl.edu/publication/IN737 · checked October 2026
Sightings recorded · Records of wild sightings (GBIF)
Counts of GBIF records of wild observations (human and machine) and preserved specimens. Records include introduced populations, vagrants, escaped or released animals and misidentifications, so a country with records is not necessarily part of the native range.
Wild sightings have been recorded in United States, Canada, Mexico, China, India, Georgia, Germany, UK and 1 more places.
Source: gbif · checked October 2026
Range maps show where scientists say an animal lives, often country by country. An animal may live in only part of a country shown, and sightings records can include animals that wandered far from home.
A moth that never eats
Luna moth caterpillars eat tree leaves.
They munch walnut, hickory, sweetgum and birch leaves. The grown-up moth has no working mouth. It never eats at all!
All of a luna moth's eating happens while it is a caterpillar. The green caterpillars munch the leaves of trees such as walnut, hickory, sweetgum, persimmon, sumac and white birch.
The adult moth does not eat at all. Its mouthparts are vestigial, which means they are left over from its ancestors and no longer work. That is why grown-up luna moths live for only about a week.
Larvae feed on broadleaf trees. Northernmost populations most often use white birch (Betula papyrifera); more southerly ones use members of the walnut family, such as walnuts and hickories, plus sumacs, sweetgum and persimmon. A 1989 study by Lindroth and colleagues found that first-instar survival was poor on some plants reported as hosts, suggesting that different geographic populations are adapted to different host plants. Luna caterpillars are never common enough to seriously damage their trees.
Adults have vestigial mouthparts and do not feed at all, so they are short-lived: the Chesapeake Bay Program gives an adult life of less than 10 days.
Did you know?
Luna moths were on a stamp.
In 1987 the United States issued a first-class postage stamp with a luna moth on it.
Described by Petiver in 1700, the luna was the first North American saturniid reported in the literature; it appeared on a US first-class stamp in 1987.
Feathery antennae and twisting tails
A luna moth has feathery feelers on its head.
Its body is fuzzy and white. It has four green wings with round spots. The back wings have long tails that twist.
A luna moth has a thick, fuzzy body and four broad green wings. Each wing has an eyespot, and each back wing has a long tail. In flight, these twisting tails may confuse bats.
Its antennae look like little feathers: they are comb-shaped on four sides. A male's antennae are bigger than a female's. Females give off a special scent that can draw males from far away. Males are more yellowish green, and females are more blue-green.
Luna antennae are quadripectinate, comb-like on four sides, and larger in males; females release a sex-attractant pheromone that can draw males from a distance. Males are more yellowish green and females more blue-green.
Eyespots sit in the center of both forewings and hindwings, and the Chesapeake Bay Program notes that the four eyespots confuse predators. The long hindwing tails twist in flight; experiments by Barber and colleagues (2015) and Lee and Moss (2016) support the idea that they interfere with the echolocation of hunting bats, drawing attacks away from the body. The adult even carries serrated spurs on its thorax, near the bases of the front wings, which it uses to cut its way out of the cocoon.
Egg to moth
A luna moth starts as a tiny egg on a leaf.
A green caterpillar hatches and eats lots of leaves. It wraps itself in a leafy cocoon. Inside, it changes into a moth.
A female lays 200 to 400 eggs on leaves, one at a time or in small groups. After about one to two weeks, tiny caterpillars hatch. They grow through five stages, shedding their skin each time, until they are bright green and about 5.5 to 7 centimeters long.
Just before it changes, the caterpillar turns reddish. It spins a silk cocoon wrapped in leaves, and inside, it becomes a pupa. Cocoons spun in autumn fall to the ground with the leaves. The new moth comes out in the morning, so its wings can dry before it flies that night.
Females lay 200 to 400 eggs, singly or in small clusters, which incubate for 7 to 13 days. The solitary larvae pass through five instars, from 6 to 8 millimeters long in the first to 55 to 70 millimeters when full-grown, and development from hatching to pupation takes a month or longer, depending on temperature. Caterpillars exposed to short day lengths produce diapausing pupae, which pause their development, while long days produce pupae that develop straight away.
The single-layered cocoon is spun among host-plant leaves and is not anchored to a twig, so autumn cocoons fall with the leaves. Adults usually emerge in the morning, males several days before females, which leaves time for the wings to expand and dry before the evening flight. On its first day the moth releases meconium, a reddish liquid made of waste from breaking down its larval tissues.
Night flyers
Luna moths fly at night.
They love bright lights. Luna caterpillars stay safe by being green like leaves. If something bothers them, they make a little clicking sound.
Luna moths are strong fliers that come out at night. Males can fly a long way to find a female. They are drawn to bright lights, and people often find them near houses and buildings.
Bats, owls and other birds all hunt luna moths. The caterpillars hide by being as green as the leaves. If a hungry animal bothers one, the caterpillar rears up the front of its body and clicks its jaws as a warning, sometimes spitting up a bad-tasting liquid.
Adults are strongly attracted to light, particularly ultraviolet wavelengths. Mating usually happens in the first hours after midnight, and females begin laying eggs the following evening, continuing for several nights.
The luna's defenses change with its stage. Caterpillars rely on cryptic green coloring; when threatened they rear the front of the body in a sphinx pose and click their mandibles, sometimes with defensive regurgitation of distasteful fluid. Brown and colleagues (2007) found that the regurgitant of a related moth deterred ants and mice and suggested that clicking warns of it. Adults face bats, owls, birds and parasitic flies; one study found the ground below an owl roost littered with saturniid wings, including those of luna moths.
Did you know?
A new luna moth cuts its way out of its cocoon.
A new moth uses tiny saw-edged spurs near its front wings to cut its way out of its cocoon.
Serrated chitinous spurs on the thorax, near the forewing bases, cut the exit hole after the moth splits the pupal case.
Helping luna moths
Luna moths are still common.
But bright lights at night can confuse them. Turning off outdoor lights helps moths find each other.
Luna moths are still common, but in some places there are fewer than before. Losing forests is one problem. Bright lights at night are another: moths are pulled toward lights, which can stop them from finding mates.
You can help by turning off outdoor lights you are not using, and by keeping native trees like walnut, hickory, birch and sweetgum in yards and parks.
NatureServe ranks the luna moth G5, globally secure, and Butterflies and Moths of North America calls it common. The Chesapeake Bay Program notes that light pollution, which disrupts mating, and habitat destruction have caused declines, though the species is still considered common.
Scientists have raised a specific concern about artificial light: the University of Florida cites work suggesting that bright sources such as mercury vapor streetlights may deter luna and other silk moths from mating and harm populations in cities. Turning off unneeded outdoor lights and keeping native host trees are simple ways to help.
Did you know?
A grown-up luna moth has no working mouth.
Adult luna moths have vestigial mouthparts that do not work, so they never eat and live only about a week.
Adults have vestigial mouthparts and do not feed; the Chesapeake Bay Program notes this is common among silk moths.
Amazing facts
-
A grown-up luna moth has no working mouth.
Adult luna moths have vestigial mouthparts that do not work, so they never eat and live only about a week.
Adults have vestigial mouthparts and do not feed; the Chesapeake Bay Program notes this is common among silk moths.
-
Luna caterpillars click when they are bothered.
If attacked, a luna caterpillar clicks its jaws, sometimes before spitting up a bad-tasting liquid.
Mandible clicking may serve as an acoustic warning of defensive regurgitation, as Brown and colleagues (2007) suggested for related moths.
-
Luna moths were on a stamp.
In 1987 the United States issued a first-class postage stamp with a luna moth on it.
Described by Petiver in 1700, the luna was the first North American saturniid reported in the literature; it appeared on a US first-class stamp in 1987.
-
A new luna moth cuts its way out of its cocoon.
A new moth uses tiny saw-edged spurs near its front wings to cut its way out of its cocoon.
Serrated chitinous spurs on the thorax, near the forewing bases, cut the exit hole after the moth splits the pupal case.
Words to know
- vestigial
- left over from an animal's ancestors and no longer working
- cocoon
- a silk case a caterpillar spins around itself before it changes into a moth
- echolocation
- finding things by making sounds and listening for the echoes
- eyespot
- a round marking that looks like an eye
- nocturnal
- active at night
- pheromone
- a scent an animal gives off to send a message to others of its kind
Discovery challenge
-
What does a grown-up luna moth eat?
What does an adult luna moth eat?
What does an adult luna moth feed on?
- Nectar
- Nothing at all
- Leaves
Show the answer
Nothing at all
Nothing! The grown-up moth has no working mouth.
Its mouthparts are vestigial, so the adult never eats. Only the caterpillar eats leaves.
Adults have vestigial mouthparts and do not feed; all feeding happens in the larval stage.
-
What might the luna moth's long tails trick?
Which hunters might the luna moth's twisting tails confuse?
Which predators' echolocation are the hindwing tails believed to disrupt?
- Bats
- Fish
- Frogs
Show the answer
Bats
Bats! The twisting tails may trick a bat into grabbing a tail.
Bats hunt by listening for echoes, and the spinning tails may draw their attacks away from the moth's body.
Studies (Barber et al. 2015; Lee and Moss 2016) support the idea that twisted tails deflect bat echolocation attacks.
-
Where does a luna caterpillar change into a moth?
What does a luna caterpillar make before it changes into a moth?
Which structure protects the luna moth pupa?
- A nest of mud
- A silk cocoon wrapped in leaves
- A hole in a tree
Show the answer
A silk cocoon wrapped in leaves
It spins a silk cocoon wrapped in leaves.
It spins a silk cocoon wrapped in leaves; autumn cocoons fall to the ground with the leaves.
A single-layered silk cocoon spun among host leaves, not anchored to a twig, so it falls with the leaves in autumn.
-
When do luna moths fly?
When are adult luna moths active?
When does luna moth mating usually take place?
- At night
- At noon
- Only in winter
Show the answer
At night
They fly at night.
They come out at night, and they are drawn to bright lights.
Mating usually happens in the first hours after midnight; females lay eggs from the next evening.
Places where you might see it
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United States
The United States is a large country in North America made of 50 states, from icy Alaska to the warm islands of Hawaii. It has the Grand Canyon, the Mississippi River and Yellowstone, and about 342 million people live there.
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Country
Canada
Canada is the second-largest country in the world, stretching across the north of North America from the Atlantic to the Pacific and up into the Arctic. It has the Rocky Mountains, thousands of islands and about 42 million people, who speak English, French and many other languages.
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United States
The United States is a large country in North America made of 50 states, from icy Alaska to the warm islands of Hawaii. It has the Grand Canyon, the Mississippi River and Yellowstone, and about 342 million people live there.
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Country
Canada
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The atlas moth is one of the largest moths in the world, with wings up to about 24 centimeters across. It lives in tropical and subtropical forests of southern and Southeast Asia. Its caterpillars eat a lot and spin silk cocoons, and the adults cannot eat at all: they live for only about a week.
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For parents & teachers
What children will learn
- Describe the luna moth's four life stages and how long each lasts.
- Explain why an adult that cannot eat lives only a short time.
- Describe how the luna's tails, eyespots and caterpillar behaviors help it avoid predators.
- Explain how outdoor lighting can affect night-flying insects.
Recommended ages: 3 to 17 · About 15 minutes
Talk about it
- If you could only live for one week, what would matter most? How is that like a luna moth?
- Why might twisting tails help a moth escape a bat that hunts with sound?
- What could your family or school do to reduce bright light at night?
Try at home or in class
- Cut a moth shape from paper with long tails, spin it on a string and watch how the tails twist and flutter.
- On a summer evening, leave a porch light on for an hour with a grown-up and count the kinds of moths that visit, then switch it off.
Key vocabulary: vestigial, cocoon, echolocation, eyespot, nocturnal, pheromone
Where these facts come from
- GBIF Backbone Taxonomy and GBIF Occurrence Search , Global Biodiversity Information Facility (CC0 1.0 (backbone); occurrence counts are facts derived from records under CC0, CC BY and CC BY-NC)
- Wikidata , Wikimedia Foundation (CC0 1.0)
- Luna Moth, Actias (=Tropaea) luna (EENY-411) , University of Florida, IFAS Extension (Featured Creatures)
- Luna Moth , Chesapeake Bay Program
- Luna Moth, Actias luna , Butterflies and Moths of North America
- Wikimedia Commons , Wikimedia Foundation (Per file: Public domain, CC0, CC BY or CC BY-SA only (credited on each page))
Checked, not yet human-reviewed. Last updated October 27, 2026. Spotted a mistake? Tell us.