Current Locust Situation and News
Locust Situation March 2014
This page summarises the known distribution of locusts during February and provides a brief outlook to May 2014. The next Locust Bulletin will be produced April 2014.
- Australian Plague Locust situation
- Spur–throated Locust situation
- Migratory Locust situation
- Map of forecasting regions
The widespread rainfall in most inland regions during February has produced suitable vegetation and soil conditions for locust breeding. Adult population densities remained low during January and February, so egg laying initiated by heavy rainfall is only likely to produce low and some medium density nymphs during March. The only known area where nymphs developed during February is part of Central West Queensland, south-east of Longreach. Fledging of nymphs in this region in late February could provide a higher density breeding population to take advantage of further heavy rainfall during the second half of February. A more significant nymphal generation is therefore possible in Central West Queensland than in other regions during March. Only limited surveys were conducted during February, due to continued very dry conditions, staff commitments to field research and road access restrictions late in the month. Surveys are planned for most regions during March, following the abrupt change to more favourable habitat conditions.
In New South Wales, limited surveys of parts of the Central West, Far West, Far Southwest and northern Riverina regions identified low density adults. There were consistent low density and medium density adults in a few locations, but locusts were mainly restricted to remaining green vegetation along road verges. No nymphs were detected during surveys.
In Queensland, limited survey was conducted in the part of the Central West region with a vegetation response to storm rainfall in mid-January. No adults were detected, but low density mid-instar nymphs were identified at several locations between Isisford and Ilfracombe in the Longreach Regional Council area. These were produced by local breeding in response to the heavy storm rains in mid-January.
No surveys were conducted in South Australia during February. Conditions remained very dry in most of the state until mid-February and previous surveys detected very few locusts, so any locust breeding after the recent rainfall is likely to result in only a small population increase. No surveys were conducted in Victoria as regulatory authority for APLC survey has yet to be provided. Low density adults were identified near Bendigo by Victorian Department of Environment and Primary Industries staff in mid-February.
This was the third consecutive summer in which no known high density populations developed in inland eastern Australia. The February rains will provide the opportunity for a late generation of nymphs during March and April, but two generations of increase are generally required for swarm populations to develop from very low densities. The outlook for autumn therefore is for moderate population increases from very low levels in Queensland and New South Wales in April and May. The development of any swarm density locusts is likely to be restricted to localised habitat areas. Adult populations are likely to increase to medium densities in the Central West and Southwest regions of Queensland, and possibly in the Central West, Far West, Far Southwest and Riverina regions of New South Wales. Some low density migration and redistribution is therefore 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.
There is a widespread but very low density adult population in most regions of inland Queensland. There has been a gradual decline in detected adult numbers during recent months. The first indication of breeding in surveyed regions was the identification of low density mid-instar nymphs at one location near Isisford, south of Longreach on 18 February. Low numbers of adults were identified the Central West, Northwest and Central Highlands regions of Queensland in recent months, but only occasional adults in Southwest and South Central Queensland. Very few adults have been recorded in New South Wales.Rainfall in the Central Highlands, Gulf Country, Northwest and Central West regions of Queensland during recent months has initiated breeding and some egg laying. However, very few nymphs have been detected so far this season, indicating a low level of breeding activity at least in surveyed regions. The current population level is very much below the average identified in previous years. There is a low risk of a significant infestation developing during 2014.
Surveys during summer have not detected this species, but the Central Highlands of Queensland, where populations develop more frequently, has not been surveyed in recent months. There have been no reports of locust activity. However, gregarisation can occur at local scales, often associated with summer cropping in Queensland, and can therefore be difficult to detect without intensive surveys. The risk of any widespread infestation developing in 2014 remains low.
4 March 2014
Circles indicate locations of APLC light traps.
Shaded areas indicate potential locusts habitat areas.
11 Mar 2014