Based on the climate in which they live, the luna moths produce differing numbers of generations. In Canada and northern regions, they can live up to 7 days and will produce only one generation per year. These reach adulthood from early June to early July. In the northeastern United States around New Jersey or New York, the moths produce two generations each year. The first of these appear in April and May, and the second group can be seen approximately nine to eleven weeks later. In the southern United States, there can be as many as three generations. These are spaced every eight to ten weeks beginning in February.

The Luna moth typically has a wingspan of 3-5 inches and rarely exceeding 7 inches with long, tapering hindwings, which have eyespots on them in order to confuse potential predators. Although rarely seen due to their very brief (1 week) adult lives, Luna moths are considered common. As with all Saturniidae, the adults do not eat or have mouths. They emerge as adults solely to mate and party-down and as such, only live approximately one week. They are more commonly seen at night. The males are distinguished from the females by their larger and wider antennae.