The “most beautiful” claim may be an exaggeration. But only the coldest heart could be immune to the ethereal splendor of a luna moth undulating through the night. That spectral flight plays out in deciduous woodlands throughout the eastern half of North America. In northern climes, spring is the prime viewing time. In southernmost regions, where three generations of luna moths may cycle through one year, adult moths can be seen from March through August.
An often opalescent pale green, the luna moth does indeed undulate more than fly, as it coordinates its huge fore and hind wings. The wingspan measures nearly 5 inches. Enhancing the slow, sensuous flight is an extravagantly long “tail,” an extension of the hind wings.
From some perspectives, the tail seems swallow-like. But the luna moth is not built for speedy maneuvering like the swallow, which needs an agile rudder to snatch bugs on the wing. Dinner is the last thing on the mind of an adult luna moth, which never eats and has only vestigial mouth parts. In the seven days it spends as a night-flying beauty, it has a single purpose: mating.
Pheromones, the Perfume of Luna Moth Love
For that purpose, visual splendor is less important than chemical appeal. The chemists of Chanel would be hard pressed to come up with a more effective pheromone than that of a female luna moth. She exudes her special scent as she perches on the bark of such favorite trees as sycamores, black walnuts, hickories or persimmons.
Following that scent through the night air is the male luna. He can track female pheromones through the densest canopy, thanks to his prominent, well-haired antennae. Those feathery-looking antennae provide the key visual clue, distinguishing male from female.
Once the male finds his true love, the pair will copulate for nearly a day. It is a great and rare treat to see such a couple, seemingly in joint stasis. But they are very much alive as they tend to the survival of the species.
After separating from the male, the female will seek out the appropriate vegetation for her eggs. The underside of black walnut leaves is a favorite spot. The idea is to have a ready food source, once each hungry caterpillar leaves the egg.
Within a few days of mating, the adult male and female die.
The Hazards of Being a Luna Moth
It takes no small measure of luck for the luna moth to survive long enough to mate and deposit eggs. In every phase of its life cycle, it is food for a wide range of predators, from wasps to owls to bats.
Like many moths, the luna wears two large “eyes” on its wings. Those false eyes suggest something far less vulnerable than a moth. The overall green coloring provides further camouflage by day, as the luna hunkers down among leaves.
The luna also relies on movement to fool predators. Fluttery wing strokes are designed to unnerve enemies, to make them think twice before striking.
Actias Luna and Homo Sapiens
The luna moth faces risks from man, as well. Destruction of the moth’s woodland habitat threatens the species’ survival. And bright manmade lighting disrupts the mating cycle of luna moths, as they blunder toward neon signs and lighted windows — and far away from the woods where they have the best chance of finding and attracting mates.
Nevertheless, the luna moth is not considered an endangered species.
Although a silk moth, the luna offers humankind little by way of material value. It is not an efficient producer of silk. And the silk it produces is not hardy enough for commercial exploitation.
Conversely, the luna moth poses no threat to man’s material interests. Although luna caterpillars feed on leaves, the net damage to trees is minimal. Unlike gypsy moth larvae, which devastate specific types of trees (oaks, in particular), luna caterpillars have a more eclectic palate. Nor do they spawn in such prodigious numbers as to threaten the very woodland on which they depend.
For man, the value of the luna moth is not quantifiable. The pale green creature is a symbol of ephemeral beauty. As it retreats deeper into the woods for its own survival, fewer people are likely to experience that beauty for themselves.