(order Orthoptera, family Acrididae)
Name given to several species of acridids which show density-related changes in their morphology and behaviour. At low population densities the insects develop as solitary, cryptically coloured grasshoppers (phase solitaria). At higher densities, such as may result from an abundance of food after rain, the insects develop into gregarious, brightly coloured individuals, which swarm and migrate, often causing great destruction to vegetation (phase gregaria). Major species include Locusta migratoria (migratory locust), Schistocerca gregaria (desert locust), and Nomadacris septemfasciata (red locust).
Subjects: Ecology and Conservation — Zoology and Animal Sciences.