What insect order includes grasshoppers, crickets, and locusts?

The insect order that includes grasshoppers, crickets, and locusts is Orthoptera.

Orthoptera contains two major living branches: Caelifera, which includes grasshoppers and locusts, and Ensifera, which includes crickets, katydids, and related insects. More than 20,000 orthopteran species are distributed worldwide, occupying habitats from grasslands and deserts to forests and caves.

The name Orthoptera comes from Greek words meaning “straight wing.” Members generally have powerful hind legs adapted for jumping, chewing mouthparts, and forewings that are narrower and more leathery than their membranous hindwings. They develop through incomplete metamorphosis, so young nymphs resemble smaller, wingless adults.

Sound is another familiar orthopteran trait. Crickets and katydids commonly produce songs by rubbing body parts together, while many grasshoppers stridulate with their legs and wings. Locusts are not a separate order: they are grasshoppers that can develop a swarming, migratory phase under suitable conditions.