Australian plague locust update

Situation update – autumn 2025

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

There were few locust activity reports in Victoria during autumn 2025. Limited sporadic breeding is possible under suitable habitat conditions in the Mallee and Wimmera districts but any resulting populations are likely to remain at low levels. There is a very low risk of regional infestations developing.

Locust populations remained at low to medium levels across inland eastern Australia. Most habitats in the arid/semi-arid interior of eastern Australia, which received 0–10 mm of rainfall, remained unfavourable for locust breeding.

The overall outlook is for low to medium-density populations across inland eastern Australia, with possible localised high densities of nymphs developing in central west NSW and inland Queensland.

If rainfall increases as predicted, migration may occur into favourable inland areas and it is likely that some small locust bands will develop from untreated populations if this occurs.

There is a low likelihood of widespread infestation developing during autumn.

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.