What causes the increase in locust populations?
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. When there are several wet seasons (winter, spring and summer) locusts can complete several generations in a single year. This results in overcrowding of developing nymphs (young insect stage) and stimulates the change to the gregarious, swarming phase. 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.
