Current Locust Situation and News

Locust situation May 2013

This page summarises the known distribution of locusts during April 2013 and provides a brief outlook to Spring 2013. The next Locust Bulletin will be produced in Spring 2013.

• Australian Plague Locust situation  
• Spur–throated Locust situation 
• Migratory Locust situation
• Map of forecasting regions

Australian Plague Locust (Chortoicetes terminifera)

Adult populations remained at low densities in most regions during April. A localised infestation of high density adults and a number of small swarms developed in the eastern part of Central West New South Wales, following the fledging of locally produced nymphs. Medium density adults and low density mid-instar nymphs were identified in a few locations in Quilpie Shire in South West Queensland in early April.

Surveys in New South Wales in early April identified a number of swarms of young adults in the Gilgandra–Collie area of the Central West Livestock Health and Pest Authority (LHPA). In mid April high density adults and small swarms remained in this area and a proportion of females were developing eggs. There were also high numbers of the eastern plague grasshopper (Oedaleus australis), mixed with locusts in some locations in that area, contributing to the overall swarm densities. At this stage no swarm egg laying has been reported. Elsewhere in Central West and Lachlan LHPA areas only low density adults were identified. Only occasional adults were identified in other regions, apart from more consistent low densities in the Jerilderie–Narrandera and Darlington Point areas.

Adult population densities remained low in surveyed areas of Southwest and Central West Queensland during April. However, localised medium density adults and low density mid-instar nymphs were identified in the Mt Howitt and Eromanga areas in the Southwest region in early April. Only occasional adults were detected elsewhere in these regions.

No surveys were conducted in South Australia or Victoria during April. There were reports of very low numbers of adults in the Bendigo–Kerang area of North Central Victoria in late March. There is unlikely to be any significant spring populations in these states.

The outlook is for low population levels to continue in most regions during May and there is a low probability of nymphal infestations in spring. However, the localised high density adults in the Gilgandra–Dubbo area of Central West New South Wales persisted throughout April and some sporadic swarm egg laying may have occurred, possibly extending into May. The majority of eggs laid in April will enter diapause and hatch in late August and September. There is a moderate probability of a medium density nymphal generation developing in parts of the Central West during spring, with the possibility of small bands in some locations, but at this stage there is a low risk of a widespread infestation.

In Western Australia, moderate adult locust activity was reported in parts of the Central Agricultural region, including Shires of Lake Grace, Merredin and Bruce Rock and Kellerberrin during April. No information is available on any autumn egg laying in these areas. 

3 April 2013 

Spur–throated Locust (Austracris guttulosa)

Adult population densities declined in inland regions of Queensland and New South Wales as the summer breeding adults came to the end of their lifespan and numbers of fledging nymphs have been very low. Surveys in April identified Isolated and some Scattered density adults, with only occasional nymphs in Central West Queensland. The extent of successful breeding during summer appears to have been limited, as few nymphs have been detected by surveys during the entire summer-autumn period.

April surveys in Queensland identified Isolated–Scattered density adults in parts of Longreach and Barcaldine, and Blackall-Tambo Regional Council (RC) areas, while in other parts of the Central West and Southwest regions there were occasional Isolated density adults. Very few adults were detected in New South Wales.

The population is much smaller than autumn populations in recent years. The late onset of the northern wet season and lower than average rainfall received is likely to have reduced successful nymphal recruitment and a low level overwintering population is expected in most regions. The outlook presents a low risk of an infestation developing during 2013.          

Migratory Locust (Locusta migratoria)

Surveys were conducted in the Central West region of Queensland, and the New South Wales Central West during April. Occasional Isolated density adults were identified in the Blackall–Tambo and Barcaldine Regional Council areas. Areas of the New South Wales Northwest Plains and South Central Queensland, where Scattered density adults were identified in previous months, were not surveyed.

This species is capable of continuous breeding and of producing several generations in a year, which can lead to the development of infestations. With the restriction of heavy rainfall to the parts of the Central Highlands in April, following repeated heavy rainfall during summer, the possibility of small gregarious populations developing in autumn remains. However, no reports of this species have been received, and the risk of a widespread infestation developing in 2013 remains low.

Map of locust forecasting regions mentioned on this web page

Circles indicate locations of APLC light traps.
Shaded areas indicate potential locusts habitat areas.