Current Locust Situation and News
Locust situation in November 2009
This page summarises the known distribution of locusts during early November 2009 and provides a brief outlook to mid-December 2009. The next Locust Bulletin will be published in December 2009.
- Australian Plague Locust situation
- Forecast development dates
- Spur-throated Locust situation
- Migratory Locust situation
Australian Plague Locust (Chortoicetes terminifera)
Swarms formed in a number of locations in Central West New South Wales during the first half of November. Swarms were first recorded in the Coonamble–Gulargambone–Baradine and Collie–Warren areas where localised high density egg laying began from 4 November. In mid-November swarms formed in the Trangie–Tullamore and the Peak Hill–Parkes areas. While most swarm activity has been in the eastern half of the Central West Livestock Health and Pest Authority (LHPA) area, there are some swarms in adjacent parts of Central North and Lachlan LHPA areas. There were residual nymphs at various stages of development in many areas in mid-November. A localised swarm infestation also developed to the north of Narrandera in Riverina LHPA area.
The outlook is for declining swarm activity in the Coonamble–Gulargambone–Baradine area during the second half of November, but an increase in the Collie–Warren–Trangie and Tullamore–Peak Hill areas. At this stage only very localised high density egg laying has been identified in an area east of Coonamble in Central West New South Wales and there is little evidence of significant migration to other areas. Forecast dates for possible egg laying have been adjusted in the table below as a result of this as well as continued above-average temperatures and forecast rainfall. Hatching from identified egg beds will occur in late November and produce a second generation of nymphs and some hopper bands during December. Conditions are favourable for nymphal for nymphal survival. There remains a potential for some migration of adults from Central West New South Wales to other regions in New South Wales and southern Queensland during the second half of November.
Surveys in western New South Wales identified medium density young adults in the Ivanhoe–Mossgiel area in mid-November and widespread low density late instar nymphs in the Condobolin–Hillston area and in the Lachlan and eastern Riverina LHPA areas. Several swarms of young adults formed north of Binya-Barellan in the Riverina LHPA as a local infestation of nymphs fledged in mid-November.
There was no significant population change in Queensland during early November, despite heavy rainfall in the South Central and Darling Downs regions at the end of October. Surveys identified a low density population in those regions and in Central West and Southwest Queensland.
No locust activity has been reported from South Australia and vegetation remains very dry in the Far Northeast region. Rainfall in the southern Flinders Ranges area and parts of the Northwest region during October has produced suitable conditions for locust breeding and an increase in population is possible.
Low numbers of adults and mid-instar nymphs were reported from the Echuca area in North Central Victoria in mid-October. Some small-scale immigration into Northwest Victoria from Far Southwest New South Wales is possible in late November.
In Western Australia nymphs were reported from the Southern Cross, Merredin and Lake Grace areas Central Agricultural region, and the Salmon Gums and Jerramungup areas in the Western Agricultural region during October. Several swarms were reported in the Southern Cross area in early November and Department of Agriculture and Food officers are monitoring the situation.
Forecast development dates for indicative locations in NSW, Queensland and South Australia
| Location - NSW | Egg laying# | Hatching | Mid-instar | Fledging |
|---|---|---|---|---|
| Coonamble-Baradine | 6 November | 23 November | 2 December | 17 December |
| Collie-Trangie | 24 November | 12 December | 32 December | 14 January |
| Peak Hill-Parkes | 28 November | 18 December | 26 December | 20 January |
| Nyngan-Tullamore | 11 November | 2 December | 12 December | 27 December |
| Condobolin-Hillston |
- |
- |
9 November | 23 November |
| Narrabri - Wee-Waa* | 11 November | 3 December | 13 December | 27 December |
|
Location - Qld |
Egg laying | Hatching | Mid-instar | Fledging |
| Birdsville-Thargomindah* | 27 November | 13 December | 21 December | 5 January |
| Quilpie-Blackall | 5 November | 22 November | 1 December | 15 December |
|
Location - SA |
Egg laying | Hatching | Mid-instar | Fledging |
| Coober Pedy* | 12 October | 31 October | 11 November | 26 November |
| Hawker-Orroroo* | 12 October | 9 November | 20 November | 6 December |
Forecast dates in the table above are based on development models for egg laying by known or possible adult populations and assume sufficient soil moisture for direct development. Models use recorded and longtern average temperatures. Dates indicate the start of the majority of the population entering the life stage. Forecast dates will be updated regularly. Expect variation around these dates as any actual egg laying will vary from nominated dates and hatchings could extend for several weeks.*No known significant population. #Projected egg laying beyond the date of this update is based on development stage of current population and forecast rainfall.
Spur-throated Locust (Austracris guttulosa)
There were several reports of swarms in the Mt Isa area in Northwest Queensland during October. The number of locusts caught in the Julia Creek light trap fell during October and Novmber after high numbers during August and September. Surveys November identified a widespread Scattered–Numerous density adult population in Central West Queensland, and mainly Isolated density adults in the Central Highlands and South Central Queensland, and the Northwest Plains of New South Wales.
The development of over-wintering swarms is common in Queensland after immature adults redistribute in late autumn. These swarms feed on tall grasses and trees during winter. Adults will migrate and disperse to commence breeding from the start of the northern wet season.
Migratory Locust (Locusta migratoria)
This species was not observed during surveys in October and November.
19 November 2009