Migratory locust

• Large, heavily built locust with adult body 14–60mm long.
• Adults vary from green to brown in ordinary circumstances to straw-coloured when swarming.
• Nymphs can be dark or striking black and tan.
• Adults have fine hair on chest.
• Adult flight is strong and steady, with slight green tinge visible on wing.

• Confined mostly to Queensland's Central Highlands, with smaller populations further south.
• See the locusts fact sheet (PDF, 5MB) for distribution maps.

• Nymphs and adults can be found year-round.
• Damaging populations are restricted to warmer months.
• In normal summer temperatures, minimum life cycle is:
  • eggs hatch after 11 days, producing nymphs
  • nymphs then take 30 days to become immature adults
  • immature adults take further 14 days to mature and lay eggs.

• Sorghum, sugar cane, forage, wheat crops.

Economic

• Damages pasture and crops.
• Avoid losses by planting less susceptible crops such as sunflower, chickpea, safflower and cotton.

• Insectivorous birds and mammals, predator insects, parasites and diseases.

• Readily controlled with insecticides if treated at the right time.
• Different insecticides can be used to control locust species.
• Residues of some insecticides have negative effects on trade in agricultural products.
• Only insecticides registered or approved for use to control migratory locust by the Australian Pesticides and Veterinary Medicines Authority can be used in Queensland’s cropping or livestock producing areas.
• Control of the migratory locust is a landholder’s responsibility.
• Biosecurity Queensland is responsible for recommending and coordinating control strategies in Queensland.
• The Australian Plague Locust Commission implements control measures when locusts reach sufficient numbers to present a threat to 2 or more states.
• Appropriate application methods for insecticides used to control locusts vary with the locusts' life stages and behaviour.

Nymphs - ground spraying

• Nymph bands are the best targets for ground spraying using agricultural chemicals. Migratory locusts readily form nymph bands, which can best be seen early morning and late afternoon from the air or from raised areas. Large nymph bands can be sprayed with boom sprays. Isolated and small areas can be sprayed using misting machines or knapsack sprayers.
• No licence is required to control locusts on your own property using insecticides from ground-spraying equipment.
• When using agricultural insecticides, you must read and follow all product label instructions.
• Although all bands are worthy of control, best results are achieved if control is undertaken when nymphs are in the smallest area.
• Factors influencing movement of nymph bands and effectiveness of control include nymph density, weather and cover.
• Nymphs at densities below 30 insects per m² move very little and don't form bands.
• Spraying in the late afternoon is most effective, as nymphs tend to spread out during the day. Strong winds may cause nymphs to shelter in cracks in the ground or behind windbreaks.
• Dense, high pasture or crops should not be sprayed in still conditions, as wind turbulence is needed for spray to penetrate foliage.
• Nymphs die after contact with, or ingestion of, treated vegetation. This may be 2–48 hours after spraying. Follow-up treatments may be necessary for up to 2 weeks after spraying, as several waves of bands will hatch from 1 egg bed.

Fledged and flying locusts – aerial spraying

• Once locusts have fledged or are flying, aerial spraying with agricultural insecticides is the only efficient control method.
• The aerial application of agricultural insecticides is a regulated activity under the Agricultural Chemical Distribution Control Act 1966.
• Aerial spraying should be undertaken by a licensed aerial distribution contractor. Pilots in command of aircraft must hold a current pilot chemical rating licence.

• The migratory locust is not a prohibited or restricted invasive animal under the Biosecurity Act 2014. However, by law, everyone has a general biosecurity obligation (GBO) to take reasonable and practical steps to minimise the risks associated with invasive animals under their control.
• Local governments must have a biosecurity plan that covers invasive animals in their area. This plan may include actions to be taken for migratory locust. Some of these actions may be required under local laws. Contact your local government for more information.