What Do Caterpillars Eat?

Caterpillars, the larvae of butterflies and moths, feed almost exclusively on plants. You will find most caterpillars munching happily on leaves, though some will feed on other plant parts, like seeds or flowers.

Generalist Feeders vs. Specialist Feeders

Herbivorous caterpillars fall into one of two categories: generalist feeders, or specialist feeders. Generalist caterpillars feed on a variety of plants. Mourning cloak caterpillars, for example, will feed on willow, elm, aspen, paper birch, cottonwood, and hackberry. Black swallowtail caterpillars will feed on any member of the parsley family: parsley, fennel, carrot, dill, or even Queen Anne's lace. Specialist caterpillars restrict their feeding to smaller, related groups of plants. The monarch caterpillar feeds only on the foliage of milkweed plants.

A small number of caterpillars are carnivorous, usually feeding on small, soft-bodied insects like aphids. One rather unusual moth caterpillar (Ceratophaga vicinella) found in the southeastern U.S., feeds exclusively on the shells of dead gopher tortoises. Tortoise shells are made of keratin, which is tough for most scavengers to digest.

Determining What to Feed Your Caterpillar

Whether a caterpillar specializes on a specific type of plant or feeds on a variety of host plants, you will need to identify its food preferences if you're going to raise it in captivity. You can't put a caterpillar in a container with grass and expect it to adapt to eating something different than its usual diet.

So how do you know what to feed it, if you don't know what kind of caterpillar it is? Look around the area where you found it. Was it ​on a plant? Collect some foliage from that plant and try feeding it that. Otherwise, gather samples of whatever plants were nearby, and watch to see if it chooses a certain one.

Also, keep in mind that we often find caterpillars when they're wandering away from their host plants, looking for a place to pupate. So if the caterpillar you collected was crossing a sidewalk or trudging across your lawn when you picked it up, it might not be interested in food at all. 

Oak Leaves: The (Nearly) Universal Caterpillar Food

If your caterpillar won't eat anything you've offered it, try collecting some oak leaves. An incredible number of moth and butterfly species—well over 500—will feed on oak leaves, so the odds are in your favor if you try Quercus leaves. Other foods that are preferred by many caterpillars are cherry, willow, or apple leaves. When all else fails, try leaves from one of the powerhouse perennials for caterpillars.

Host Plants for Caterpillars to Eat in Your Garden

If you want to plant a true butterfly garden, you need more than nectar plants. Caterpillars need food, too! Include caterpillar host plants, and you'll attract a lot more butterflies as they visit your plants to lay eggs.

When you plan your butterfly garden, include some caterpillar host plants from this list. A well-designed butterfly garden supports not only this year's butterflies but generations of butterflies to come!

Common Garden Butterflies and Their Host Plants