Katydid,( family Tettigoniidae ) also spelled bush cricket. Katydids are widespread, occurring in every region of the world with the exception of Antarctica.
Katydids are a large group of insects in the order Orthoptera, related to the grasshoppers and crickets. Some katydids have been called long-horned grasshoppers because of their long and slender shape, but actually katydids are more closely related to crickets than to any type of grasshopper. There are about 6,400 species worldwide, with the greatest diversity in the tropics.
Many species are leaf-shaped to blend in even better with their environment to prevent predation. They tend to be poor flyers. Katydids display remarkable adaptations for defense, a consequence in part of their generally poor flying ability, which leaves them highly vulnerable to predation. Cryptically coloured species, which blend in with the environment, rely primarily on the mimicry of vegetation. The peacock katydid (Pterochroza ocellata), for example, precisely mimics the discoloration of a dead leaf.
Katydids are usually green and camouflaged to blend in with foliage, more commonly heard than seen. They have a body taller than it is wide and thin and hind legs that are longer than the other pairs of legs. Some characteristics that distinguish katydids from other orthopterans include having the wings held vertically over body , and very long, thin antennae as long as or longer than the body. In grasshoppers the antennae are always relatively short and thickened.
The antennae are covered with sensory receptors that help them find their way around in the dark, since they are primarily nocturnal.
The common true katydid produces the repetitive song for which katydids are named; the song is phoneticized as : katy-did, katy-didn't.