Australian plague locust swarms can devastate crops and cause major agricultural damage. It is vital that landholders know what to do if you suspect plague locusts in NSW. Local Land Services staff can help you identify and control plague locusts on your property.

What are plague locusts

Locusts are large herbivorous insects that can form dense and highly mobile swarms.

There are 3 main pest locust species in Australia:

  • the Australian plague locust (Chortoicetes terminifera)
  • the spur-throated locust (Austracris guttulosa)
  • the migratory locust (Locusta migratoria).

Of the 3 species, Australian plague locusts are the most important due to their ability to produce several generations in one year and infest large areas and devastate crops and pastures.

How to identify plague locusts

Australian plague locusts can be identified from other species by the dark spots on the tips of their hind wings and distinctive red hindleg shanks. Another distinctive feature is the x-shaped marking behind their head which becomes more visible with maturity. Their body colour can vary anywhere from grey, brown and green.

Adult male locusts measure from 25-30 mm long and the tip of their abdomen is smooth and rounded. Adult females measure from 30-42 mm long and the tip of their abdomen is jagged.

Young first instar nymphs are usually pale in colour varying to brown and grey and are around 3 mm in size when they hatch. As they develop through the instar stages it becomes easier to identify them as Australian plague locusts.

The difference between a grasshopper and a locust can often be confused as they look similar in appearance, however locusts behave in different states depending on the density of the population. In high density populations, locusts undergo behavioural changes and form gregariously behaving bands of nymphs or swarms.

What problems are caused by locust swarms

Locusts swarms can cause damage to vegetation, crops and pastures when they move through landscapes in bands which can lead to large economic losses for affected landholders.

Green plants are normally the target feed for locusts with green pastures (particularly grass species) at risk of locust attack. Pressure on individual crops will depend on whether there is alternative feed available, or whether obstacles such as tree lines affect locusts from moving through the landscape.

Your local biosecurity officer can assist you with how to prevent locusts attack on your crops and pastures.

How to report signs of plague locusts

Reporting signs of Australian plague locusts to your Local Land Services biosecurity officer is vital for the successful monitoring and control of these pest insects.

Landholders should report sightings of locusts to help build a picture of the statewide situation. Reports are used to forecast locust movements, breeding, impacts and required control strategies.

Local Land Services biosecurity staff are trained in identification of Australian plague locusts and can help landholders to control locust populations before they form swarms.

Plague locust control

Controlling Australian plague locusts is essential to limit their impact on our agricultural industries.

Effective control of plague locusts is most effective when landholders work together to monitor, report sightings, and undertake control programs.

Our staff work with landholders, the NSW Department of Primary Industries, the NSW Farmers' Association, and the Australian Plague Locust Commission in manage locust populations and reduce the damage they cause.

Obligations to control plague locusts

All landholders have a legal obligation to report any of the 3 locust species (Australian plague, spur-throated and migratory locusts) to their Local Land Services office.

Also, all land managers have a general biosecurity duty under the NSW Biosecurity Act 2015, meaning they need to prevent, eliminate or minimise biosecurity risks as far as reasonably practicable.

This means landholders have an obligation to eradicate plague locusts on their property.

What support is available for locust control

Our biosecurity staff are trained to identify locusts, and their biology and control options, so can advise you on the most effective way to manage them on your land.

Our specialist staff can issue landholders with pesticide to spray detected bands of locusts.

Several pesticides are registered for the control of spur-throated locusts. Your local biosecurity officer can advise on eradication methods and provide insecticide to ratepayers.

All control should be undertaken as per the label or off label permit instructions.

How to control plague locusts

It’s vital that ground-control activities for locusts are carried out at the banding stage (third instar) to save time and reduce the need for a second spray for later hatching locusts.

This will also reduce the risk of residue concerns associated with the chemical application.

It’s also extremely important that the situation is monitored closely before and after control activities.

Effective control of swarms is mostly done by aerial spraying, targeted at juvenile adults while they are roosting in the evening or early morning.

For more information on pest species and biosecurity, visit PestSmart and the Department of Primary Industries.

Otherwise, please contact your local biosecurity officer if you require locust or pest insect management advice.

Locust control resources

The NSW Department of industries has a series of factsheets on chemical use, forms, equipment, biology, behaviour and industry-specific information.

The Australian Plague Locust Commission is jointly funded by the Australian Government and the member states of New South Wales, Victoria, South Australia and Queensland. It has a series of resources on identifying Australian locust, the current locust situation, insecticides and the history of locust in Australia.

How are pest species managed in my region?

We've worked with regional pest animal committees and the community to develop regional strategic pest animal management plans in each of our 11 Local Land Services regions.

Your Regional Strategic Pest Animal Management Plan will tell you what priority pest animal pest animals you need to manage and how.

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