Luna Moth Life Cycle

Several months ago, we were given the gift of a dozen or so Luna Moth (Actias luna) cocoons, which hatched to reveal the stunning pale green wings and trailing tails that make this species one of our most spectacular moths. Tampa is at the very southern edge of the Luna Moth range, so it's not often we get a chance to see these night-flying beauties. Even more exciting - our moths mated, providing us with a plethora of eggs to raise!

Luna Moths don't waste any time when it comes to mating. As a member of the silk moth family, these adult moths don't have functional mouth parts and must rely on fat stored up during their time as larvae. They mate within hours of eclosing (hatching) from their cocoons, and lay their pale gray eggs shortly thereafter. Within about 5 days, the males and females have used up their fat reserves and die, leaving the next generation to carry on in the months ahead.

Luna moth host plants vary by region. In the northern part of their range (which stretches up the Eastern half of the U.S. to Canada), they favor the leaves of white birch trees (Betula papyrifera). In the southern part of their range, which includes Florida, they feed on sweetgum (Liquidamber styraciflua), persimmon (Diospyros virginiana), and hickory (Carya sp.). Here at MOSI Outside, we decided to feed our Luna moth larvae on sweetgum, since it was easily available to us from our Historic Tree Grove.

Unlike most butterfly larvae which are ready to pupate in just a couple of weeks, Luna moth larvae eat for nearly two months. This is partly because the tree leaves they consume are tougher to digest, and partly because of the enormous size they attain before making their cocoons. By the last few weeks, these caterpillars are consuming large branches of leaves each day, making them difficult to keep up with!

Luna moth larvae look extremely similar to another silk moth caterpillar, that of the Polyphemus Moth (Antheraea polyphemus). Some sources list ways to tell the two apart, but despite working closely with the larvae of both species, we at MOSI Outside are unable to tell the difference. (If you have any good tips, please tell us in the comments section below!)

When Luna moth larvae are ready to pupate, they lose their bright green coloration and instead turn a brownish-orange (shown above). They spin a tough cocoon of silk, often incorporating nearby leaves and twigs. Inside the cocoon, the caterpillar sheds its skin one final time, becoming a dark brown pupa. These pupa can be very active in their cocoons, wriggling like mad when disturbed to scare off possible predators.

In the southern part of its range, the Luna moth may have up to three generations each year. In the far north, though, it has only one, meaning the adults moths are visible for just a few nights each year as they find mates and lay eggs. Most of us are lucky to see a Luna moth adult even once in our lifetimes, making it all the more special that we've had the chance to raise this species at MOSI Outside this summer. See more photos of adult Luna moths at MOSI Outside by clicking here.