Caterpillars are simply butterfly and moth larvae – the stage before the adult stage. Some of the answers to the question above can be nothing, everything or a favorite plant. However that is not the case all the time. Each species is going to be different from the next one and their dietary needs may be a bit different depending on the adult species in question. Also there are beneficial caterpillars and pest caterpillars. They can be selective eaters depending on breed. Each one may eat a specific plant or leaf in order to grow. So what do they eat?
Caterpillars and trees
There are many different species that live on trees. They can include but are not limited to the following species: giant swallowtail, eastern tent, forest tent, red humped, yellow necked, walnut and spiny elm. Some of these can be very destructive to trees, although the adult butterflies will not harm these trees.
Leaves and shrubs
Certain caterpillars will need certain shrubs and leaves to survive into adulthood. For example, monarch caterpillars will feed on swamp milkweed while the swallowtail will feed on rue and other poisonous plants. Milkweed larvae will feed on fig or mulberry leaves while Ulysses feeds on pink flowered doughwood.
There are several different varieties of butterfly caterpillar that are considered pests. The cabbage white butterfly larvae are deposited on cabbage plants while the tiger swallowtail larvae will eat black cherry leaves. Pearl crescent will eat asters, buckeye prefers to eat garden flowers and viceroy in apple, plum or cherry trees is considered a considered pest.
Beneficial caterpillar species include the painted lady, which uses thistle, the red banded hairstreak which uses fallen oak leaves, and the monarch, which uses milkweed as their host plant. Some of the beneficial species feed on aphids. So not all butterfly larvae are destructive to plants. The diets of these beautiful butterflies will vary by species. Each one will need something different than the other species and it is noted that not every single species will be beneficial.