Australian plague locust update

Situation Update – Spring 2025

Australian plague locusts (Chortoicetes terminifera) are native insects that, if left unmanaged, pose a serious threat to pastures, crops and horticulture.

The Australian plague locust population remained at low to medium levels across inland eastern Australia during autumn but increased in central Queensland.

Rainfall was highest on record east of Charleville in Queensland in autumn with some areas receiving more than 600 mm. However, much of the arid and semi-arid interior received below-average rainfall during April and May becoming unfavourable for locust breeding.

The outlook for spring is low-density populations across inland eastern Australia, with localised higher densities of nymphs possible in parts of central west New South Wales and inland Queensland. The overall likelihood of widespread infestations developing in spring remains low, however.

Victorian outlook

In Victoria, low density adults were seen in the north-west in autumn. Limited sporadic breeding is possible in Victoria if habitat is suitable but any resulting population is likely to remain at low levels. There is a very low risk of a regional infestations developing in spring.

Migratory locust

Recent reports of large locust swarms in Queensland refer to the Migratory locust (Locusta migratoria), the less damaging cousin to the Australian Plague Locust in Australia.  Despite its name, the Migratory Locust does not migrate long distances as often or as far as the Australian Plague Locust. Swarming populations of Migratory locusts are mainly restricted to Central Queensland.  Intermittently, they extend into northern New South Wales but do not reach Victoria.

The population of the Migratory locusts increased markedly in Queensland in autumn and there is a moderate to high risk of a regional infestation developing in central Queensland during spring.

A summary of locust activity throughout Australia is provided by the Australian Plague Locust Commission via the Locust Bulletin.

Where are locusts found?

Locusts naturally inhabit the far north-west of NSW and adjacent areas of Queensland and South Australia and the south-west region of Western Australia.

Intermittent locust populations may also be seen in varying concentrations from season to season around regional Victoria. In any given year, it is possible that locust swarms could migrate into Victoria from interstate.

Who is responsible for managing locusts?

In Victoria, government, public land managers, private landholders and the community all have a role to play in managing locust populations and minimising their impact.

Landholders are responsible for reporting and managing locusts on their land.

Agriculture Victoria continues to undertake surveillance and works closely with all stakeholders to provide relevant, timely and accurate information on locust populations and movements throughout the season.

Locust management strategies

Ground control using a chemical insecticide is the most successful method to manage locusts. The most effective time to spray locusts is at the second or third instar stage (around two weeks after hatching), when hoppers are wingless and band densities reach or exceed 80 hoppers per square metre. At this stage, hoppers form large, slow-moving bands, providing a clear target for efficient and effective insecticide use. Programs to treat adult flying locusts are generally ineffective.

For more information about various control options for the management of locusts, see Managing Australian plague locusts.

Further information:

Managing Australian plague locusts

Information for households and gardeners

Australian plague locust – biology and behaviour.

Visit Agriculture Victoria's Australian plague locust online learning module page for a twenty-minute interactive short learning course.