Luna moth caterpillars eat the leaves of several native North American hardwood trees, including sweetgum, birch, hickory, walnut, persimmon, and sumac. Their diet is entirely plant-based and limited to fresh foliage, which they consume in large quantities across five larval stages before spinning a cocoon.
Primary Host Trees
Luna moth caterpillars feed on a surprisingly wide range of deciduous trees. White oak, hickory, red maple, and river birch are among their most common food sources. Sweetgum and persimmon are also well-documented hosts, particularly in the southeastern United States. In northern parts of their range, white birch and paper birch become more important food sources.
Other trees luna moth caterpillars will eat include walnut, sumac, and beech. The specific trees a caterpillar feeds on depend largely on what’s available in its habitat. A female luna moth typically lays her eggs directly on or near a suitable host tree, so the caterpillar begins eating whatever species it hatches on.
Regional Differences in Diet
Luna moths live across a wide swath of eastern North America, from southern Canada down to Florida and west into Texas. This range covers very different forests, and the caterpillars adapt to local tree species. In the Great Lakes region, birch tends to dominate their diet. Farther south, sweetgum, persimmon, and hickory are more commonly used. In mid-Atlantic and northeastern forests, walnut and oak play a bigger role.
This flexibility is one reason luna moths can survive across such a broad geographic range. They aren’t locked into a single tree species the way some specialist caterpillars are.
How Much They Eat
Luna moth caterpillars go through five growth stages (called instars) over roughly 3 to 4 weeks. During this time, they grow from tiny hatchlings a few millimeters long to plump, bright green caterpillars about 3.5 inches in length. That growth requires an enormous amount of food. A single caterpillar can consume several full leaves per day during its final instar, and groups of caterpillars on the same tree can visibly strip small branches.
This feeding frenzy isn’t just about growing bigger. Every calorie the caterpillar stores during this stage has to sustain it through pupation and its entire adult life. Adult luna moths have no functional mouthparts. Their proboscis, the coiled tube that butterflies and many moths use to drink nectar, is vestigial and completely nonfunctional. Adults live roughly one week after emerging from the cocoon, running entirely on energy banked during the caterpillar phase.
Feeding Luna Moth Caterpillars in Captivity
If you’re raising luna moth caterpillars at home, the key is providing fresh cuttings from one of their known host trees. Birch, sweetgum, and walnut are popular choices among hobbyists because they’re easy to find and caterpillars accept them readily. Stick cut branches in bottles or containers filled with water, the same way you’d keep cut flowers fresh. Close any opening in the container with paper towel or aluminum foil so caterpillars can’t crawl in and drown.
Replace the food plant every 2 to 3 days to keep leaves from wilting or drying out. Caterpillars eat less enthusiastically once foliage starts to deteriorate. Clean the cage at the same frequency, removing droppings (called frass) so they don’t accumulate and promote mold. Provide plenty of leaves per caterpillar, especially during the later instars when appetites spike dramatically.
One important handling tip: never pull a caterpillar off a branch. Their grip is strong enough that forcing them loose can injure their legs. Instead, use scissors to cut the twig or leaf section they’re sitting on and move the whole piece to fresh foliage. They’ll migrate to the new food on their own.
What They Won’t Eat
Luna moth caterpillars are strict leaf eaters. They don’t consume fruit, bark, flowers, or other plant material. They also won’t eat leaves from non-host trees. Offering pine, spruce, or other conifers won’t work, and most ornamental shrubs are rejected too. If a caterpillar refuses to eat what you’ve offered, it likely isn’t a suitable host species. Stick to native hardwoods within the list of known hosts: birch, walnut, hickory, sweetgum, oak, persimmon, sumac, or maple.
Freshness matters as well. Caterpillars sometimes reject leaves that have been treated with pesticides or that have started to yellow. If you’re collecting leaves from the wild, avoid trees near roadsides or agricultural fields where chemical exposure is more likely.