Australian plague locust: frequently asked questions

Page last updated: Monday, 27 June 2022 - 9:55am

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This page answers some frequently asked questions about the Australian plague locust.

Locust biology and ecology

What is the difference between a grasshopper and a locust?

The difference is purely behavioural. Locusts can occur in two phases, solitary and gregarious. In the solitary phase they act just like grasshoppers but in the gregarious phase they come together to form bands and swarms.

What is the incubation period of locust eggs?

The incubation period depends on temperature and whether the eggs enter a state of diapause. With cool temperatures and eggs entering diapause (period of dormancy) over winter, the incubation period is four to five months. During summer, the incubation period is around two weeks.

What causes a locust plague?

Locust plagues begin when widespread areas of inland Australia receive good rainfall. Rainfall is necessary for locust eggs to complete their development, it stimulates growth of grasses which are required as the food source for the developing locusts and it initiates breeding in the adult locusts. Consequently, if long distance migratory flights bring the locusts into the Wheatbelt of Western Australia, there is the potential for a locust plague.


Contact information

Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080