Luna Moth Caterpillars Thrive on Hosta Leaves in the Garden

The Majestic Luna Moth and Its Favorite Hosta

The luna moth is one of the most striking and beautiful moths found in North America. With long trailing tails and lime green colored wings, the luna moth looks almost otherworldly as it floats gracefully through the night sky.

Although adult luna moths live for only about a week and do not eat, the larval caterpillars have hearty appetites. One of their favorite foods? The leaves of hosta plants.

The Lifecycle of the Luna Moth

The lifecycle of the luna moth begins in late summer when females lay up to 200 pale green eggs on the underside of hosta leaves. The eggs overwinter and hatch the following spring.

When the tiny caterpillars first emerge, they immediately begin feeding on the hosta leaves. As the caterpillars grow over the next month, they shed their exoskeletons several times. Eventually reaching 2-3 inches in length, the caterpillars take on a light green hue with yellow stripes and red spots.

Making a Cocoon on the Hosta

When the luna moth caterpillars are fully grown, they crawl to the underside of a hosta leaf and spin themselves into a thin, brown, oval-shaped cocoon made of silk. Safely tucked away, the caterpillar transforms into a pupa inside this protective casing.

About two weeks later when metamorphosis is complete, the adult moth emerges from the cocoon. With freshly pumped wings, it waits for nightfall before taking flight to continue the lifecycle.

Reasons Luna Moths Are Drawn to Hostas

So why are luna moths so often found on hosta plants? There are a few key reasons:

Abundance of Foliage

Hostas are herbaceous perennials that come back year after year. A mature hosta contains many large leaves stemming from the base that provide ample food for hungry caterpillars.

Hostas also grow quickly, so even if a luna moth caterpillar eats an entire leaf, the hosta will soon generate new leaves for sustained eating.

Accessibility

With their wide, flat leaves and short stature, hostas provide easy access for female luna moths who want a convenient place to lay eggs. The horizontal presentation of the leaves also gives newly hatched caterpillars a landing pad as they emerge and start searching for their first meal.

Sheltered Undersides

The undersides of hosta leaves offer protection from predators and weather. Female moths take advantage of this safe spot to hide their eggs, while older caterpillars and forming pupae anchor to the undersides when spinning their cocoons.

Best Hostas to Attract Luna Moths

While luna moth caterpillars will feed on all varieties of hostas, some types are more attractive than others. When selecting hosta plants for your garden if you hope to draw this beautiful moth, look for these top picks:

Blue Hostas

The blue-green color of varieties like Blue Angel, Blue Mouse Ears, and Blue Cadet closely resembles the natural foliage that luna moth caterpillars feed on in the wild. This familiar hue acts as a beacon to females looking to lay eggs.

Large Leaf Hostas

Big leaf hostas like Sum and Substance, Empress Wu, and Big Daddy provide an abundant food source with less energy expended by caterpillars traveling between leaves.

Ruffled Foliage

The textured leaves of hostas such as Spritzer, Curly Fries, and Marilyn Monroe offer more hideaways for larvae and pupae to safely tuck away from predators.

Supporting the Lifecycle of Luna Moths

By planting the preferred hostas for luna moth caterpillars, gardeners can help sustain populations of this magical insect. Supporting this ephemeral creature at all stages of its wondrous, yet fleeting lifecycle brings joy and wonder to the gardening experience.

So next time you spy a luna moth resting silently on a hosta leaf as day breaks, feel grateful to have borne witness even briefly to its beauty before it fades away with the rising sun.

FAQs

What time of year are luna moth caterpillars found on hostas?

Luna moth caterpillars are spotted on hostas in the spring and early summer months. The caterpillars hatch from eggs laid the previous late summer and feed on hosta leaves through early June.

Will luna moth caterpillars damage my hosta plants?

While luna moth caterpillars do eat hosta leaves, the plants typically recover quickly, especially when mature and well-established. Supporting the caterpillars for a few weeks is worth it to sustain the moth lifecycle.

Can I handle luna moth caterpillars found on my hostas?

It's best not to touch any wild caterpillars. Not only could you accidentally harm them, but some species have stinging hairs as defense mechanisms that could irritate human skin.

What should I do if I find a luna moth cocoon on my hosta?

Consider yourself lucky! Avoid touching or relocating the cocoon so the pupating caterpillar inside can fully transform. In about two weeks, an adult luna moth will emerge from the cocoon.