Australian plague locust situation update

Australian plague locusts (Chortoicetes terminifera) are native insects that, if left unmanaged, pose a serious threat to pastures, crops and horticulture. While its native range is in Queensland and New South Wales, outbreaks can intermittently occur in Victoria.

Situation update: July 2026, outlook to spring

Victoria

There is a higher chance of locust activity in north-west Victoria in spring. This has increased since the June 2026 update. This is because there has been good rainfall, more egg laying and higher locust numbers in New South Wales (NSW) and South Australia (SA). These locusts could move into Victoria.

For the Mallee region, there is a moderate to high chance of high locust numbers in spring. Eggs are expected to hatch from mid-September. This is about one week earlier than first expected.

For the Wimmera/Grampians region, there is a low to moderate chance of high locust numbers in spring. Eggs are expected to hatch from late September. This is about one week earlier than first expected.

Prepare your chemical and management plans.

Agriculture Victoria worked with the Australian Plague Locust Commission to survey north-west Victoria in mid-May. The survey followed reports of high locust activity in late April. The survey found low to medium numbers of adult locusts across the area.

Most adult female locusts sampled had developing eggs or signs they had laid eggs. Widespread egg laying could not be confirmed. Another round of egg laying happened in NSW and SA in late May. This probably also happened in north-west Victoria, but ground staff could not confirm it.

Above-average autumn rainfall in north-west Victoria means some habitats should stay suitable for locust breeding. Soil moisture should be high enough for eggs to develop. This is despite the Bureau of Meteorology forecast for below-average rainfall and warmer winter temperatures from a developing El Niño. Eggs are expected to hatch in Victoria from late September. This is likely to lead to high numbers of nymphs in some areas.

Eastern Australia

Locust numbers increased a lot in autumn. They changed from low background levels to medium to high levels in inland eastern Australia. Heavy rainfall created suitable habitat. Warm autumn weather also helped locusts move south and south-east.

In south-west NSW and lower eastern SA, there is a moderate to high chance of significant hatching in early spring. There is also a moderate to high chance of locust movement in late spring. Overall, there is a moderate to high risk of regional infestations.

Who is responsible for managing locusts?

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

All landholders and land managers are responsible for reporting and managing locusts on their land.

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

Victoria is a member of the Australian Plague Locust Commission, a joint partnership between the Australian Government and the state governments of Victoria, NSW, Queensland and SA. The commission undertakes surveillance throughout south-eastern Australia and provides information on current and future locust activity.

Locust management strategies

Chemical insecticide ground spraying is the most successful way to manage locusts. The best time to control locusts is around 2 weeks after hatching when they are young and cannot fly (at the nymph stage). At this stage the young locusts (nymphs) are between 8 and 12 mm long and start to band together (Fig. 1).

Managing locusts can be difficult, especially at the adult stage when they are highly mobile and moving in swarms. Spraying eggs is also ineffective, as the eggs are laid well beneath the soil.

Diagram showing the locust life cycle from eggs to adult, including growth stages (instars), with early stages highlighted as targets for insecticide application.

For more information about various control options for the management of locusts, see Chemical use and crop residues

Further information

Visit Agriculture Victoria’s Australian plague locust online learning module page for a 20-minute interactive short learning course.

Reporting locusts

Please report locust activity on your property. Reporting helps Agriculture Victoria monitor locust activity across the state. The monitoring helps us produce accurate forecasts on locust activity, including timing of hatching and densities. Public and private land managers can use this information to pinpoint where and when to spray, to reduce overall numbers and help protect Victoria’s agriculture industry.