thumbnail|right|Nymph of Locust ''Schistocera americana'' with distinct wing-rudiments
thumb|right|Locust from the 1915 Locust Plague
"Locust" is the name given to the swarming phase of short-horned grasshoppers of the family Acrididae. The origins and apparent extinction of certain species of locust—some of which reach 6 inches (15 cm) in length—are unclear.
These are species that can breed rapidly under suitable conditions and subsequently become gregarious and migratory. They form bands as nymphs and swarms as adults- both of which can travel great distances, rapidly stripping fields and greatly damaging crops.
Some examples of Locust species are:-
*Migratory locust (''Locusta migratoria'')
*Red locust (''Nomadracis septemfasciata'')
*Australian plague locust (''Chortoicetes terminifera'')
*Desert locust (''Schistocerca gregaria''), probably the most important in terms of its very wide distribution (North Africa, Middle East, and Indian subcontinent) and its ability to migrate very widely.