Luna Moths: Are They Rare, Why They Don’t Eat, Where They Live

Most people meet a luna moth only a few times, usually on a porch wall or window screen in the morning, so it seems rare. It is common; it is just hard to see, because the adult flies at night for about a week and the cocoon spends winter hidden in fallen leaves.

What is a luna moth?

A luna moth is a member of the Saturniidae, the giant silk moths, the same family as the cecropia, polyphemus, io and imperial moths. Its name comes from Luna, the Roman moon goddess, a reference to the moon-like eyespots on its wings. Clemson notes it is also called the American moon moth, and UF/IFAS records that it was the first North American silk moth reported in the literature, in 1700.

How to identify one

• Colour: pale or lime green, described by Clemson as sea-foam green to yellow, with a dark leading edge on the forewings (MDC).
• Tails: a long tail on each hindwing. The Missouri Department of Conservation says the colour and tails distinguish it from all other North American moths.
• Eyespots: one on each of the four wings.
• Male or female: males have broad, feathery antennae and are slightly smaller and lighter green; females have slender antennae and, according to UF/IFAS, tend to be more blue-green.
• Season form: where there are several broods, spring moths are deeper green with reddish-purple margins and later ones more yellow (Clemson, UF/IFAS).

How big is a luna moth?

UF/IFAS gives a wingspan of 75 to 105 mm (3 to 4.1 inches); Clemson gives 3 to 4.5 inches and MDC 3 to 4.25 inches. Southern moths tend to be smaller. That is mid-sized for a giant silk moth: smaller than a cecropia, larger than an io.

Compiled by The Pest Control Brief from Missouri Department of Conservation field guides and UF/IFAS EENY-411. The caterpillars are the harder pair to separate: MDC notes the polyphemus caterpillar looks quite similar, but its yellow bands cross the breathing pores near the middle of each segment, while the luna caterpillar’s lines sit at the rear edge of each segment.

Are luna moths rare or endangered?

No on both counts, and this is where most popular pages are vague. NatureServe, the network that assigns conservation ranks to North American species, ranks the luna moth G5, demonstrably secure globally, with national ranks of N5 in both the United States and Canada. It is not listed under the Endangered Species Act. NatureServe’s assessment states that luna moths occur in virtually every patch of forest in the eastern USA and southern Canada, except in parts of New England.

Compiled by The Pest Control Brief from NatureServe Explorer, element record for Actias luna, accessed October 2026. Only nine US states appear in the record, and every state that has assigned a rank lists the moth as secure. The US Fish and Wildlife Service ECOS species database lists no Actias species under the Endangered Species Act.

It is not untouched. NatureServe records a short-term trend of a decline of under 30 per cent to relatively stable, with substantial losses in much of southern New England. Its main named threat is Compsilura concinnata, a fly introduced to control the spongy moth that also parasitises native silk moths. Even so, NatureServe says the luna moth appears unthreatened in about 90 per cent or more of its range and has recovered since a low point in the 1970s.

Light pollution

UF/IFAS describes adults as strongly attracted to light, particularly ultraviolet, and notes concern that street lights may deter silk moths from mating in towns. The evidence is mixed: a 1988 review in the Journal of the Lepidopterists’ Society found that northeastern silk moth declines in the 1950s coincided with aerial spraying against gypsy moth, and that silk moth population changes correlated poorly with outdoor lighting. Lighting is a plausible local pressure, not a proven cause of decline. Our guide to why moths are attracted to light explains what the newest research shows and which bulbs draw the fewest moths.

Where do luna moths live?

UF/IFAS puts the range in every eastern state from Maine to Florida, west to eastern Texas and eastern North Dakota, and in southern Canada from Nova Scotia to Saskatchewan. They live in and near deciduous woodland, where the host trees grow.

Our analysis of 59,976 US research-grade iNaturalist records shows where people actually photograph them. Corrected for how much people record in each state, Georgia leads with 24.63 luna moth records per 10,000 observations of anything, followed by Alabama (22.75) and North Carolina (22.4). North Carolina has the most records outright, 6,426. Texas has 4,508 records but only 4.07 per 10,000, since most of the state lies outside the range; California has 4 and Colorado none.

When are luna moths out?

The number of generations a year depends on latitude.

Compiled by The Pest Control Brief from UF/IFAS EENY-411, Clemson HGIC 2515 and the Missouri Department of Conservation.

Our iNaturalist data show those broods stacked together. Sightings jump in March as the southern first brood emerges, run at about twice their usual share from May to August and peak in August at 232 on our seasonality index. By October they have nearly vanished. Giant silk moths as a whole peak a month earlier, in July.

Do luna moths have mouths?

They have mouthparts, but they do not work. UF/IFAS states that adults have vestigial mouthparts and do not feed, and are therefore short lived. Clemson explains that they lack a fully functional proboscis, the long sucking tube other moths use for nectar. Pages claiming they have no mouth at all overstate it: the parts are there, reduced and functionless.

All the adult’s energy was stored by the caterpillar. Clemson says adults live about one week; males may fly long distances to find a mate, and females die after laying eggs. UF/IFAS adds that mating usually happens in the first couple of hours after midnight.

What do luna moths eat?

Only the caterpillar eats. Clemson lists alder, birch, beech, red maple, white oak, wild cherry, hazelnut, hickories, pecan, walnut, persimmon, sweetgum, willows and smooth sumac. Regional preference matters: UF/IFAS says northern populations most often use white (paper) birch, while southern populations favour walnuts and hickories, sumacs, sweetgum and persimmon. A feeding study cited by UF/IFAS found poor survival on some plants listed as hosts in older literature, so local populations appear adapted to local trees.

Life cycle and the luna moth cocoon

Eggs are slightly oval, white mottled with brown, and at most about 1.9 by 1.6 mm (UF/IFAS). They hatch in 8 to 13 days (MDC). The caterpillar moults through five stages over 3 to 4 weeks (Clemson), reaching 55 to 70 mm, and turns reddish just before it pupates. The cocoon is thin and papery, made of silk wrapped in leaves, and unlike many polyphemus cocoons it is not anchored to a twig, so it drops to the ground with the autumn leaves and overwinters in the leaf litter.

Why is the luna moth shaking?

A luna moth that is trembling or vibrating its wings on a wall is usually warming up to fly. Large moths cannot take off with cold flight muscles. Researchers studying moth flight describe warm-up by shivering of the major flight muscles as necessary to reach a thoracic temperature suitable to sustain flight, and the paired flight muscles work against each other to make heat rather than a full wingbeat. Once the thorax is warm enough, the moth flies.

A freshly emerged adult also hangs still through the day to expand and dry its wings before its first evening flight (UF/IFAS, Clemson), and an older moth may have ragged or missing tails, which Clemson says they commonly lose to predators. Neither needs help.

What the tails are for

In a 2015 PNAS study pitting luna moths against big brown bats, the spinning tails drew 55 per cent of attacks on intact moths, and moths with tails had a survival advantage of about 47 per cent over moths with their tails removed (Barber and colleagues).

How to get rid of luna moths

There is nothing to get rid of. A luna moth does no damage, cannot bite and lives about a week, and UF/IFAS says the caterpillars are never common enough to cause significant damage to their host trees, so spraying for them is not warranted.

1. Leave it where it is. A moth resting on a wall by day is waiting for dark and will leave on its own.
2. Turn off or change the porch light if you would rather they did not gather by the door. They are drawn to ultraviolet light; warm white LEDs and shielded fixtures attract far fewer moths. Our moths and light guide compares bulb types.
3. Move it gently if it is in harm’s way: let it climb onto a stick or card and set it on a tree trunk.
4. Leave some leaf litter under host trees in autumn if you want them in future years, since that is where the cocoons spend the winter (Clemson).

If you have found a hairy or spiny caterpillar rather than a smooth green one, compare it with the puss caterpillar, a stinging species, and keep bare hands off io caterpillars, whose spines MDC says cause severe irritation in some people.

Frequently asked questions

Are luna moths rare?

No. NatureServe ranks the luna moth G5, globally secure, and says it occurs in virtually every patch of forest in the eastern United States and southern Canada, except parts of New England. It seems rare because adults fly only at night and live about a week, and the cocoons lie hidden in leaf litter. Our iNaturalist analysis counted 59,976 US research-grade records.

What is a luna moth?

A luna moth, Actias luna, is a giant silk moth in the family Saturniidae, found in eastern North America. It has pale green wings spanning about 3 to 4 inches, an eyespot on each wing and long tails on the hindwings. Its name comes from Luna, the Roman moon goddess. Adults do not feed; the green caterpillars eat the leaves of trees such as walnut, hickory, sweetgum and birch.

Are luna moths endangered?

No. The luna moth is not listed under the US Endangered Species Act, and NatureServe ranks it secure globally, in the United States and in Canada. It is ranked vulnerable or imperilled only at the western edge of its range, in Alberta and Saskatchewan. NatureServe notes declines in southern New England, linked mainly to an introduced parasitic fly, but says the moth appears unthreatened across about 90 per cent or more of its range.

Do luna moths have mouths?

They have mouthparts, but they are vestigial and do not work, according to University of Florida entomologists. Adults have no functional proboscis, so they cannot drink nectar or eat anything. They live on fat stored when they were caterpillars, which is why an adult luna moth lives only about a week. It also means a luna moth cannot bite you.

What do luna moths eat?

Adult luna moths eat nothing. The caterpillars eat the leaves of broadleaf trees. Clemson Extension lists alder, birch, beech, red maple, white oak, wild cherry, hazelnut, hickories, pecan, walnut, persimmon, sweetgum, willows and smooth sumac. Northern caterpillars mostly use white birch, while southern ones favour hickories, walnut, persimmon and sweetgum. They never eat enough to harm a healthy tree.

Sources

• University of Florida IFAS Extension, Featured Creatures EENY-411 (IN737), Luna Moth, Actias luna, by Donald W. Hall, 2007.
• Clemson Cooperative Extension, Home and Garden Information Center, Factsheet HGIC 2515, Luna Moth, revised 2020.
• Missouri Department of Conservation, Field Guide: Luna Moth, Polyphemus Moth, Cecropia Moth, Io Moth and Imperial Moth.
• NatureServe Explorer, Actias luna (Luna Moth), element global record, global rank reviewed 2017, accessed October 2026.
• Barber, J.R. et al., Moth tails divert bat attack: evolution of acoustic deflection, Proceedings of the National Academy of Sciences 112(9): 2812 to 2816, 2015.
• Frank, K.D., Impact of outdoor lighting on moths: an assessment, Journal of the Lepidopterists’ Society 42(2): 63 to 93, 1988.
• Crespo, J.G., Goller, F. and Vickers, N.J., study of pheromone-mediated pre-flight warm-up in male moths (Helicoverpa zea), University of Utah, School of Biological Sciences.
• US Fish and Wildlife Service, ECOS species database, search for genus Actias, accessed October 2026.
• The Pest Control Brief analysis of iNaturalist research-grade records, pulled October 2026.