Insects in the family Tettigoniidae are commonly called katydids or bush crickets. They have previously been known as "long-horned grasshoppers". More than 8,000 species are known. Part of the suborder Ensifera, the Tettigoniidae are the only extant (living) family in the superfamily Tettigonioidea.

Grasshoppers are a group of insects belonging to the suborder Caelifera. They are amongst what are possibly the most ancient living groups of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago.