Current Locust Situation and News

Locust Situation April 2014

This page summarises the known distribution of locusts during March and provides a brief outlook to June 2014. The next Locust Bulletin will be produced May 2014.

Australian Plague Locust (Chortoicetes terminifera)

The continued widespread rainfall during March in most inland regions maintained suitable vegetation conditions for survival of nymphs and the potential for autumn egg laying. There was an increase in adult population to medium densities in the Queensland Central Highlands and to consistent low densities in several other regions, including Central West and South Central Queensland and the New South Wales Riverina and Central West. Low density nymphs were detected in all these regions, along with some medium density nymphs in parts of the Central Highlands and South Central Queensland. Fledging of nymphs will contribute to further moderate increases in adult numbers during April. Similar small increases in population are likely to have occurred in other regions of these states. Surveys of northern South Australia identified only very low density adults.

In New South Wales, surveys of the Central West, Riverina and part of the Far Southwest regions in mid-March identified consistent low density adults, representing a small population increase over previous months. Low density mid-instar nymphs were detected in the Tullamore, Parkes–Forbes and Lake Cargelligo–Rankins Springs areas of the Central West. In late March adult numbers increased to medium density in the Trangie–Nyngan area of the Central West and, with the fledging of nymphs elsewhere in this and other regions, other localised increases are likely.

In Queensland, surveys were conducted in the Central Highlands, Central West and part of the South Central region. Medium density adults and nymphs were identified in the Comet–Arcadia area, south of Emerald in the Central Highlands. There were consistent low density adults in surveyed areas of the Central West and South Central regions, along with low density nymphs in the Blackall–Tambo district and some medium density nymphs in the Augathella–Morven area. The majority of nymphs were at mid-instar development stages in mid-March, indicating widespread low density egg laying had occurred in mid-February.

Surveys were conducted in the Far North, Northwest and Northeast regions of South Australia in mid-March. Only occasional adult locusts were identified and no nymphs were detected.

No surveys were conducted in Victoria, but low density adults were identified near Tungamah in mid-March and hatching was reported near Manangatang in Northwest Victoria at the end of the month. A small increase in locust numbers is indicated in northern Victoria, similar to that identified in NSW.

Despite the increase in population level in Queensland and New South Wales during March, no high density populations have been so far been detected and any swarm activity is likely to limited to small areas of habitat. The outlook for autumn is for further moderate population increases as the March nymph generation fledges in April, establishing medium density autumn breeding populations in some regions. Adult numbers are likely to increase to medium densities in parts of the Central West, Central Highlands, South Central and Southwest regions of Queensland, and the Central West, Far Southwest and Riverina regions of New South Wales. The majority of eggs laid by these adults will enter diapause and hatch in spring. Some low density migration and redistribution is possible during April or May, but at this late stage in the locust season the risk of a widespread infestation affecting agricultural areas in any state is very low.

Spur–throated Locust (Austracris guttulosa)

Surveys in Queensland during March identified low density nymphs of this species in the Central West, Northwest, Central Highlands and South Central regions. There were consistent Isolated density adults throughout the Central Highlands, but only occasional adults in other regions. Biosecurity Queensland reported high density adults associated with crop on a property north of Biloela in the eastern Central Highlands at the start of March. Very few adults have been recorded in New South Wales during 2013-14.

The low numbers and relatively late appearance of nymphs during 2013-14 indicates a restricted period of breeding in most regions during summer. The high density adults near Biloela may have been young adults produced by localised successful breeding in early summer. The current population level remains below the average identified in previous years. There is a low risk of a significant infestation developing during 2014.

Migratory Locust (Locusta migratoria)

Surveys during March identified low density adults at a single location southeast of Barcaldine in Central West Queensland. Survey in the Central Highlands of Queensland, where populations develop more frequently, did not detect this species and there have been no reports. Gregarisation can occur at local scales, often associated with summer cropping in Queensland, and can therefore be difficult to detect without intensive surveys. However, the risk of any widespread infestation developing in 2014 remains low.

4 April 2014 

Map of locust forecasting regions mentioned on this web page

Map of locust forecasting regions
Circles indicate locations of APLC light traps.
Shaded areas indicate potential locusts habitat areas.