In Australia locust plagues occur when widespread inland areas receive good rainfall in successive seasons. High rainfall stimulates the growth of grass which creates an ideal habitat for locust breeding. The timing of the rainfall is important. If wet seasons continue the swarming phase is prolonged. A series of dry seasons is necessary for the locust population numbers to decrease thus stimulating the change to the solitary form of the insect.
Locusts are vegetarians.
As they swarm and migrate they devastate grasslands and crops in the areas they pass through. The results are similar to the disaster caused by the rabbit plagues in Australia. Once started, a locust plague is just about impossible to stop. Various efforts have included destroying egg masses laid by migrating swarms. Hopperdozers can also be used.