Using chemicals to control locusts

Several chemicals and biological products are available to control locusts. The most suitable option depends on your crop, location, growth stage of locusts and environmental considerations.

Always read and follow the product label or permit before use.

Fipronil

Fipronil affects the locust's nervous system. Locusts are exposed when they come into contact with the chemical or consume treated vegetation.

Fipronil can be used in some pasture and sorghum crops and is also available for some aerial applications.

Key points:

• Effective at low application rates.
• Lower use rates reduce risks to mammals.
• Extremely toxic to bees and aquatic life.
• Do not use near waterways or when bees are foraging.

Malathion

Malathion is registered for locust control in cereals, pastures and non-crop areas.

Key points:

• Breaks down quickly after application.
• Effective at low application rates.
• Highly toxic to bees and aquatic life.
• Do not spray near waterways or when bees are foraging.

Fenitrothion

Fenitrothion can only be used in limited situations and must be applied according to the current directions and permit conditions. Only oil-in-water emulsion (EW) formulations can be used for control in cereals (excluding corn, maize and rice) and grazing sorghum.

Key points:

• Residues break down relatively quickly after application.
• Avoid entering treated areas for 48 hours after spraying where possible.
• If entry is necessary, wear appropriate protective clothing.

Carbaryl

Carbaryl is registered for locust control and suitable for cereals, pastures and non-crop areas.

Always check the product label for approved uses and restrictions.

Metarhizium (Green Guard®)

Metarhizium, sold as Green Guard®, is a naturally occurring fungus used to control locusts.

It infects locusts after contact and takes 1 to 3 weeks to kill them.

Metarhizium is a useful option where conventional insecticides are not suitable, such as near waterways or in environmentally sensitive areas.

Works best:

• in warm weather
• on young locusts (nymphs or hoppers).

Metarhizium is available in several formulations, including products for ground or aerial application.

Other approved chemical actives

Other chemicals approved for locust control include:

• Alpha-Cypermethrin
• Beta-Cyfluthrin
• Gamma-Cyhalothrin
• Lambda-Cyhalothrin

These chemicals are approved for specific situations under APVMA permits.

How do I spray locusts from the ground?

Ground-based spraying is the most effective way to control nymph bands.

Most spray equipment can be used, including:

• calibrated boom sprays
• boomless jets applying 50-200 L per hectare.

If a sprayer has previously been used for herbicides, thoroughly clean it before applying insecticides. This helps to prevent contamination.

Work with neighbouring landholders where possible. Surveying and treating larger areas together can improve locust control and reduce costs.

For more information, see ground-based spraying.

When is aerial spraying used?

Aerial spraying is often used during large locust outbreaks.

The Australian Plague Locust Commission (APLC) works with state governments when aerial spraying is required.

Aerial spraying must meet strict environmental and safety requirements. Factors such as terrain, environmental risks and buffer zone requirements can limit where chemicals can be applied.

Not all chemicals are approved for aerial use. Always check the product label or permit before spraying. Careful planning is needed to reduce risks to people, crops and the environment.

Aerial spraying may not be suitable near:

• homes
• towns
• waterways
• mixed farming areas
• forests

Can I use a drone to spray locusts?

Drones, also known as remote piloted aircraft (RPA), are considered a form of aerial spraying.

Drones can only be used where aerial application is permitted on the product label or permit. They must also produce the spray quality specified on the label.

For more information, see:

• drone or remotely piloted aircraft spraying
• manned aerial spraying

When should I use a licensed contractor?

Using a licensed contractor for locust chemical control helps ensure infestations are managed safely and effectively. Before hiring a contractor, make sure they hold the appropriate licence for the work being carried out. This may include a:

• Commercial Operator Licence (COL)
• Agricultural Aircraft Operator Licence (AAOL).

For more information, see Chemical licences and permits.

Chemical residues in wool, meat and milk can affect domestic and export markets.

Before spraying:

• read and follow all label directions
• check withholding periods
• understand any residue risks for livestock products.

If feed shortages are likely, plan ahead:

• Make hay or silage before spraying.
• Use stored feed while treated paddocks are under withholding periods.
• Purchase enough feed to meet livestock needs.
• Set up a suitable feeding area with water and shade.
• Keep records of chemicals used on livestock feed.

Table 1: Chemical actives approved for locust control in pasture and fodder

If crops are intended for export, check that relevant maximum residue limits (MRLs) or import tolerances exist in your target markets before spraying.

Chemical breakdown may slow when crops or pastures are no longer actively growing. Seek expert advice before applying chemicals to non-growing crops or pastures.

Locust contamination can also affect grain quality. Bulk grain handlers may reject, or downgrade grain contaminated with locust body parts. Check receival requirements with:

• Grain Trade Australia
• your grain buyer or trader.

Table 2: Chemical actives approved for locust control in grain, pasture and seed crops

Table 3: Chemical actives approved for locust control in fruit and nut trees

APVMA minor use permit PER13642 allows the use of malathion products for the control of Australian plague locusts in tree nut orchards.

Table 4: Chemical actives approved for locust control in vegetable crops

The biological control agent Metarhizium is the only active available to use for wine and table grapes.

The biological control agent Metarhizium is the only active available to use for organically grown produce.

Consult your accrediting body regarding chemical use.

What non-chemical options can I use?

For small numbers of locusts, you can try:

• removing locusts by hand where practical
• using insect mesh or shade cloth to protect plants. Avoid green materials, as locusts are attracted to green
• digging up egg beds and herding chickens through the area for them to eat
• digging ditches ahead of marching hoppers for them to fall into.

Table 5: Chemical actives approved for locust control in forestry

Table 6: Chemical actives approved for locust control in nursery and cut flower production

Table 7: Chemical actives approved for locust control on publicly managed land

Chemical control

Only use chemical products that are approved by the Australian Pesticides and Medicines Authority (APVMA) for home garden use.

Biological sprays

Metarhizium is the only biological active registered in Australia for controlling Australian plague locusts.

For more information, see the Organic farmers' section.

What non-chemical options can I use?

For small numbers of locusts, you can:

• remove locusts by hand where practical
• use insect mesh or shade cloth to protect plants
• dig up egg beds
• use chickens to help reduce locust numbers
• dig shallow trenches to trap marching hoppers.