Current locust situation
Locust situation 5 December 2019
This page summarises the known distribution of locusts during November 2019 and provides a brief outlook to March 2020. Regional information and forecasts are given in the latest locust bulletin.
Australian Plague Locust (Chortoicetes terminifera)
The locust population level remained very low over its range in eastern Australia during spring. Only occasional adults were recorded on APLC surveys and no nymphs were observed. Remaining pasture vegetation in most regions is very dry. Heavy rainfall at the start of November in parts of western Queensland and New South Wales produced a green vegetation response, creating opportunities for some low density breeding during the month. No surveys were conducted during November. Surveys commenced in early December to detect any nymph activity from possible breeding in areas that received rainfall.
Surveys in the Central West and South Central Queensland at the end of October recorded only occasional adults, while low density adults were identified in the Central Highlands. The low density population identified in Northwest and Southwest Queensland in September is likely to have declined due to continued drought conditions. There was localised heavy rainfall (>40 mm) in the Central West and moderate rainfall in parts of the South West and South Central regions at the start of November.
Surveys in New South Wales in late October identified very few locusts in the Riverina and Central West regions. Surveys in the Far West and Far Southwest regions recorded no locusts. The Bourke and Cobar districts of the Far West region received heavy rainfall in early November, with more widespread light–moderate falls in the Riverina, Far Southwest regions.
Previous surveys in the Northeast region of South Australia in October recorded no locusts. There was no significant rainfall in South Australia during November.
Limited surveys in Northwest Victoria in October did not detect any locusts. Locust numbers are expected to remain very low throughout Victoria.
The summer outlook is for very low population densities to continue in most regions of inland eastern Australia. Only low density breeding was possible in habitats that received heavy rainfall (>40 mm) at the start of November and localised nymphs could develop in Central West Queensland and Far West New South Wales during December. However, the very low adult population is only likely to produce low density nymphs and vegetation will dry out rapidly in the absence of further rain. Habitats in other regions will remain unfavourable with only limited breeding possible. The Bureau of Meteorology seasonal outlook indicates that below average rainfall and above average temperatures are likely to continue over coming months.
There is a low likelihood of high-density populations or regional infestations developing in any inland region during summer.
Spur–throated Locust (Austracris guttulosa)
The summer breeding population level remains very low. Surveys during 2018-19 indicate the current adult population is one of the lowest on record in the regions covered. Surveys during spring 2019 recorded only occasional low density adults in Queensland.
Surveys of the Central West, Central Highlands and parts of South Central Queensland at the end of October recorded only occasional adults in areas associated with residual green vegetation. No adults were recorded in New South Wales, Victoria or South Australia.
Localised heavy rainfall in parts of the Queensland Central Highlands and Central West at the start of November produced a short-lived vegetation response and some localised suitable breeding habitat. However, the very low background breeding population could produce only low density nymphs and there is likely to be high mortality without further significant rainfall.
There is a very low risk of a widespread infestation developing during summer or autumn 2020.
Migratory Locust (Locusta migratoria)
This species was not recorded on any surveys during spring. Migratory locust habitats have become increasingly dry in the Queensland Central Highlands, South Central and Central West regions where this species is more commonly observed. However, heavy rainfall in parts of the Central West region could have initiated some low density breeding during November. Given the very low prior adult population level, this is unlikely to produce more than occasional nymphs.
There is a very low risk of a widespread infestation developing during summer.
Locust forecasting regions
Map of forecasting regions with potential locust habitats shaded yellow