Current locust situation

​​​​​​​​​Locust situation 6 December 2018

This page summarises the known distribution of locusts during November 2018 and provides a brief outlook to February 2019. Regional information and forecasts are given in the latest locust bulletin.

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Australian Plague Locust (Chortoicetes terminifera)

The locust population level remains very low over its range in eastern Australia. This trend has been maintained over the last two years. Widespread drought conditions during autumn, winter and September 2018 have limited locust breeding opportunities. Habitat conditions remained dry in most regions during November, but rainfall in New South Wales and Queensland produced a limited green vegetation response in some regions. Very few adult locusts were recorded during spring and no nymphs were detected.

Survey in the Central West, Northwest Plains, Far Southwest and Riverina regions of New South Wales recorded only occasional adult locusts and no nymphs. There was light–moderate rainfall (<20-40 mm) in parts of the Riverina, Far West, Far Southwest and Northwest regions in the first half of November. There were further light-moderate falls in the Northwest and Central West regions in late November.

Survey of the Central West, South Central and Central Highlands regions of Queenslad identified very low density adult locusts in the Blackall–Longreach and Injune–Roma–Mitchell areas, with only occasional adults in other areas. There was light–moderate rainfall in the Southwest and South Central regions during the first week of November, and further light–moderate falls in those regions in the second half of the month.

Previous surveys in South Australia recorded no locusts and habitat conditions were very dry. There was localised light–moderate rainfall in parts of the Northwest and Northeast regions during November, but habitat conditions remain dry in most areas.

No surveys have been conducted in Victoria, but locust numbers are expected to be very low. There was light–moderate rainfall in the North Central region during the second half of November, but habitats remain dry in most areas.

The outlook for summer is for population densities to remain low in inland eastern Australia. The Bureau of Meteorology seasonal rainfall outlook for December to February 2019 indicates continued below average rainfall in Queensland and high temperatures are likely to persist over most of the species range. However, localised heavy rainfall events can provide breeding opportunities and subsequent nymph populations. Given the very low current population numbers in all surveyed regions, there is a low probability of successful breeding producing high density populations during December or January.

There is a low probability of a widespread infestation developing in any region during summer.

Spur–throated Locust (Austracris guttulosa)

The spring 2018 population level was lower than the spring records in recent years.

Surveys in November identified only very occasional adults in the Queensland Central West and more consistent low density adults in the Central Highlands region.

Although rainfall in the Central Highlands and South Central Queensland could have initiated some breeding during November, nymphs and eggs are susceptible to desiccation and high nymph mortality can occur if habitats become dry in December or January. The low spring population numbers in surveyed regions are unlikely to produce widespread nymphs during summer, even if there is average wet season rainfall.  Low numbers of nymphs are likely to develop in parts of these regions during December.

There is a low risk of a widespread infestation developing during summer.

Migratory Locust (Locusta migratoria)

Surveys in mid-November did not detect this species, although occasional adults were recorded in the Southern Central Highlands in October. Rainfall in the southern Central Highlands and South Central Queensland during November could allow low density breeding and the maintenance of background population numbers.

There is a low risk of a widespread infestation developing during summer.

Locust forecasting regions

Map of forecasting regions 

Map of forecasting regions with potential locust habitats shaded yellow