The larval state of a butterfly or any lepidopterous
   insect; sometimes, but less commonly, the larval state of other
   insects, as the sawflies, which are also called false caterpillars. The
   true caterpillars have three pairs of true legs, and several pairs of
   abdominal fleshy legs (prolegs) armed with hooks. Some are hairy,
   others naked. They usually feed on leaves, fruit, and succulent
   vegetables, being often very destructive, Many of them are popularly
   called worms, as the cutworm, cankerworm, army worm, cotton worm,
   silkworm.