The Luna moth (Actias luna) is a large and striking member of the giant silk moth family. This nocturnal insect emerges at night, known for its luminous appearance. Its ethereal beauty, with wings resembling delicate, moonlit leaves, makes it a remarkable creature of the North American woodlands. It belongs to a group often referred to as the “American moon moths.”
Identifying a Luna Moth
The Luna moth is distinguished by its vibrant coloration and impressive size. Its wings are typically a vivid lime-green, though some individuals may exhibit a more yellowish-green hue. These broad wings can span between 3 to 4.5 inches (8 to 11.5 cm), making it one of North America’s larger moths. Its hindwings feature long, flowing tails.
Each of the moth’s four wings displays a translucent, circular marking known as an eyespot. These eyespots often feature concentric rings of black, blue, red, yellow, or white, serving as a defense mechanism to confuse predators. The moth’s body is covered in soft, white, fuzzy hairs, contrasting with its colorful wings. Male Luna moths possess larger and more feathery antennae compared to females’ more slender antennae, which they use to detect pheromones.
The Life Cycle of the Luna Moth
The Luna moth undergoes a complete metamorphosis, transitioning through four distinct stages: egg, larva (caterpillar), pupa, and adult. Female moths lay between 200 to 400 eggs, depositing them singly or in small clusters on the underside of host plant leaves. These eggs typically incubate for 8 to 13 days before hatching.
Upon hatching, larvae (caterpillars) feed on specific tree foliage. Their diet includes leaves from sweetgum, hickory, walnut, pecan, and birch trees, among others. The caterpillars are bright green and grow through five stages, called instars, shedding their skin (molting) between each stage over 3 to 7 weeks. Once fully grown, the caterpillar descends to the ground or spins a silk cocoon, often among leaf litter.
Within this cocoon, the caterpillar transforms into a pupa, a stage lasting two to three weeks, though it can extend up to nine months if overwintering. The adult moth emerges from the cocoon with small, crumpled wings, which it expands and hardens over several hours by pumping fluid into them. Adult Luna moths have a short lifespan, living for about one week. They do not possess functional mouthparts and therefore do not feed, relying entirely on energy stored during their caterpillar stage. Their adult existence is dedicated to reproduction.
Habitat and Unique Behaviors
Luna moths are widely distributed across North America, inhabiting forested regions from Canada’s Saskatchewan and Nova Scotia eastward, and throughout the eastern and central United States, extending south to Florida and west to Texas. They primarily favor deciduous woodlands, where their larval host plants are abundant.
These moths are nocturnal, meaning they are active and fly predominantly at night. Like many nocturnal insects, Luna moths are attracted to artificial lights, which can sometimes draw them away from their natural habitats. During their short adult lives, their main objective is to locate a mate. Males are drawn to females by pheromones, which they can detect with their feathery antennae, often traveling considerable distances.