Australian Plague Locust

Fact Sheet
FS 09/00

Australian Plague Locust PDF (373 kb)Australian Plague Locusts

Plague development 

Most locust plagues originate in the Channel country of south west Queensland and adjacent areas of South Australia, New South Wales and the Northern Territory (Figure 1). Large locust populations develop following rainfall in this area.

Given suitable conditions the Autumn swarms may migrate 200 to 500 km into the State’s pastoral andadjacent agricultural areas. On arrival they lay eggs which produce the spring outbreak.

The State has had major plagues in 1844, 1871, 1934, 1947, 1955, 1976, 1979, 1992, 1993, 1997 and 2000.
Minor plagues have occurred in 1950, 1969, 1972, 1973, 1974, 1977 and 1984.

IdentificationAustralian Plague Locust

The adult of the Australian Plague Locust is relatively easy to identify by the characteristic black spot on the tip of the hind wing (photo 1).

Nymphs (hoppers) are more difficult to identify. If a large mass (band) of hoppers is found it is likely to be the plague locust.

Eggs

The adults become sexually mature within two weeks of developing wings.Australian Plague Locusts The female selects suitable laying sites (photo 2) by test drilling. These sites are
barest ground available e.g. roadsides, tracks, fence lines, dry land flats, sparse pasture paddocks etc.
Eggs are laid in pods (see photo 3) usually at a depth of 20 to 50 mm. Each pod contains 30 to 50 pale yellow banana-shaped eggs, 5 to 6 mm long. Each female can lay up to four pods before dying.  FS09005locust

Eggs develop according to temperature and moisture. Usually eggs laid in autumn are dormant over winter and hatch in the spring as soil temperature increases. However, eggs laid in summer under ideal conditions, may hatch within 14 to 16 days.

Nymphs

After hatching, nymphs (hoppers) grow through five growth stages. Wing buds become progressively more notable through each stage.Plague Locust

The nymphs move away from egg beds and often concentrate into dense marching bands (photo 4) which vary in size from a few square metres to several hectares. By merging, bands may increase to several kilometres with a distinct front. Older hoppers can travel up to 500 m in a day.

Hoppers complete their development in 4–6 weeks.

 Australian Plague Locust

Adults

After the final moult, a young adult emerges withfully developed wings. Milling flights increase over the band until the majority of hoppers have fledged. The adults concentrate into groups called swarms which make low drifting flights up to 50 m high and can cover 10 to 20 km per day. Flight behaviour depends on the age of the adult, wind speed and temperature. Long distance migration will occur at night if green feed has been available to enable fat accumulation.

Australian Plague Locusts

Control

Landowners are encouraged to undertake their own control measures. The cultivation of egg beds particularly in the agricultural areas will destroy the eggs, while the control of hoppers and adults can be achieved by using various insecticide formulations. Advice on these can be obtained from local chemical resellers.

The Australian Plague Commission (APLC) undertakes surveillance threat assessments, forecasting and control measures when locust populations in outbreak areas have the potential to cross into other states.

Local Government may also undertake spraying operations (e.g. roadsides) within their own area. Where significant problems are expected PIRSA may undertake large scale control in the pastoral and adjacent agricultural areas.

Effective suppression of locusts can only be achieved by landowner, local government and PIRSA combined cooperation together with ongoing APLC activities.

Last update: November, 2008

Agdex: 168/620

Author: Ken Henry, SARDI Entomology.

Disclaimer

Use of the information in this Fact Sheet is at your own risk.  The Department of Primary Industries and Resources and its employees do not warrant or make any representation regarding the use, or results of the use, of the information contained herein in terms of its suitability, correctness, accuracy, reliability, currency or otherwise.  The entire risk of the implementation of the information which has been provided to you is assumed by you.  All liability or responsibility to any person using the information is expressly disclaimed by the Department of Primary Industries and Resources and its employees.

Australian Plague Locusts
ISSN 1323-0409