Caterpillars are herbivores and eat plant matter, including leaves, grasses, and flowers, which make up most of their diet. However, some caterpillars are omnivores and feed on animal carcasses, red ants, aphids, and other caterpillars. Most butterflies and moths can only rely on certain plants, shrubs, or trees to feed their young. For example, the caterpillar of the monarch butterfly can only eat milkweed leaves to survive. Therefore, it is important to know which species of butterflies and moths are native to where you live and to find the native plants that host them. Here are some examples of plants that caterpillars of certain species eat:

• Acmon Blue: buckwheat, lupines, milkvetch
• American Painted Lady: cudweed, everlast
• Bairds Swallowtail: dragon sagebrush
• Black Swallowtail: parsley, fennel, carrot, dill, or even Queen Annes lace
• Monarch: milkweed leaves

If you find a caterpillar and want to feed it, some herbaceous plants such as dandelions and clover are common hosts for larvae. When all else fails, try a few bits of apple or carrot. However, it is important to note that not all caterpillars will eat the same foods, and some may have very specific dietary requirements. Therefore, it is best to identify the species of caterpillar you have and research its specific dietary needs before attempting to feed it.