Caterpillars (larvae) of Lepidoptera species (i.e. of butterflies and moths) are mostly (though not exclusively) herbivores, often oligophagous, i.e. feeding on a narrow variety of plant species (mostly on their leaves, but sometimes on fruit or other parts). Lepidopteran larvae often require specific species of food plants. It also makes some of them important pests in agriculture or forestry. The host plants have yet to be determined for some species. There is not always consensus among lepidopterists over the listing of suitable plants.