Luna moths, with their striking lime-green wings and long, flowing tails, are among North America’s most recognizable and beautiful insects. These large moths, often spanning three to seven inches across, possess distinctive eyespots on each of their four wings and a soft, white, hairy body. Their ethereal appearance has captivated observers, making them a notable presence in the continent’s deciduous forests.
Daily Activity Patterns
Luna moths are primarily nocturnal, active from dusk until dawn. During daylight, they remain still and hidden, blending with tree bark or leaves to avoid predators and conserve energy. This resting phase is important for their survival. Luna moths are strongly attracted to artificial lights, especially those emitting ultraviolet wavelengths. This attraction stems from their natural navigation method, where they orient themselves using distant light sources like the moon, becoming disoriented by closer artificial illumination.
Seasonal Flight Periods
Luna moth seasonal activity varies across their North American range, from Canada to Florida and west to the Great Plains. In northern regions, such as Canada and the northern United States, Luna moths are univoltine, producing one generation per year. Adults in these areas emerge and are active in late May or early June. Further south, in mid-Atlantic states, they are bivoltine, having two generations annually.
In the deep southern parts of their range, Luna moths can be trivoltine, completing three generations annually. The first generation may appear as early as March, with subsequent broods emerging approximately eight to ten weeks later. Moth appearance also changes seasonally; spring broods are often vivid green, while later generations may be yellowish-green.
The Adult Life Stage
The adult Luna moth stage is brief, lasting only six to ten days. This short lifespan is due to a unique biological adaptation: adult Luna moths lack functional mouthparts and cannot feed. Their entire existence as an adult relies on energy reserves accumulated during their caterpillar stage.
The primary purpose of this short adult period is reproduction. Female Luna moths release powerful sex pheromones to attract males, detectable from considerable distances by their large, feathery antennae. Mating occurs after midnight, and females begin laying eggs the following evening, continuing for several nights. This highly focused, time-sensitive reproductive drive dictates their limited and specific periods of activity.