The Beautiful, Endangered Luna Moth Is Not a Pest

Luna Moth on Geraniums
Photos by Michael Crowley/Moment/Getty Images

This article is a bit outside the standard pest control articles for this site, but when we came upon a photo of the Luna Moth while conducting general research on moths, we just had to find out more and pass it along to readers. Partly because it is so lovely and interesting; partly to make sure readers know the no pest control is needed despite its name.

If you have seen a Luna Moth for real, count yourself lucky.

This large, beautiful moth is of the Saturniidae family which is sometimes called the giant silkworm moths or American moon moths. Once a very common sight, the Luna Moth is considered to be endangered in some areas – although it is not officially on any endangered species list.

A Beautiful, Unique Moth

Although the Luna Moth larvae are large caterpillars that feed on the leaves of many shrubs and trees, their populations don't grow large enough to cause significant damage or destruction. Additionally, once it becomes an adult, the moth no longer feeds at all, nor even has a mouth by which it could feed. It will live for only about a week as an adult during which time it will mate, and the female will lay her eggs – about 200 in small batches on the underside of leaves.

Because there are so few, and they are a nocturnal insect – flying only at night, it is very rare for people to see this unique moth.

Its name: Luna, meaning moon, is attributed both to its nocturnal nature as well as the crescent in the eyespot of its wings that resembles a crescent moon.

Because of this and its beauty, the Luna Moth is not considered a pest and control efforts are not needed or desirable. In fact, the use of pesticides, loss of habitat, and pollution are some of the reasons it is endangered.

The moth's natural enemies are owls, bats, bald-faced hornets, Fiery Searcher ground beetles, and parasitic wasps. The caterpillar stage deters predators by rearing its front end in a "sphinx-like" stance, making a clicking noise with its mandibles, and regurgitating a distasteful fluid.  

Identifying the Luna Moth

The Luna is one of the largest of moths in North America with a wingspan of 4 ½ inches, additionally:

  • Its body is white, its long legs are pinkish, and its large wings are translucent lime green. Its hind wings also have eyespots and long tails to confuse predators.
  • The male's antennae are larger and bushier than the female's.
  • It is found in forested areas from eastern Canada to Florida and west to eastern Texas and North Dakota.
  • Luna moth larvae feed on plant leaves including hickory, walnut, sweet-gum, persimmon, birch trees, American beech, red maple, white oak, black cherry, willows, American chestnut, and smooth sumac.

Seen primarily in spring and early summer, the moth will generally have two generations in a year. In early spring, a moth will emerge from a cocoon in which it overwintered. Generally emerging in the morning, the moth will rest and hang through the day to allow its wings to inflate with its blood.

It will then fly off at night to seek a mate.

Once the moth mates and lays its eggs, it will die. In about 10 days, the eggs will hatch into caterpillars and immediately begin to feed. It will feed, grow, and molt about five times for 3 to 4 weeks until it is about 2 ½ inches long. At this time, it will spin its silken cocoon wrapped in a leaf. It will cocoon for two to three weeks, then emerge as an adult moth to begin the lifecycle again.

This second generation will go through the same process, however, because it will cocoon late in the season, it will stay cocooned over the winter to emerge as an adult moth in the spring.

Moth Control

Again, no control is needed for the Luna Moth, as sufficient numbers are never found to create significant damage.

References and Resources