Current Locust Situation and News
Locust situation in February 2010
This page summarises the known distribution of locusts during January 2010 and provides a brief outlook to mid-March 2010. The next Locust Bulletin will be produced in March 2010.
- Australian Plague Locust situation
- Forecast development dates
- Spur-throated Locust situation
- Migratory Locust situation
Australian Plague Locust (Chortoicetes terminifera)
Locust distribution changed substantially in several regions of Queensland and New South Wales during January as a result of fledging and migrations of populations established at the end of November.
At the start of January many bands of mid-instar and older nymphs had developed in the Noccundra–Durham Downs–Mt Howitt area of Southwest Queensland. Fledging commenced in the second week of January. The first swarms formed at that time and continued to develop throughout the month. From mid-January migrations resulted in increased population density in parts of Central West and South Central Queensland and in the Wanaaring–Bourke–Brewarrina area of Far Western New South Wales. Sporadic swarm egg laying occurred at a number of locations in Queensland after mid-January. Swarms also developed in the Walgett–Carinda area of the New South Wales Northwest Plains and in the western Riverina, south of Balranald, in late January.
The outlook is for localised high density nymphal populations to develop in several regions of Queensland and New South Wales during February. Hopper bands are likely in the first half of February in eastern Bulloo and Quilpie Shires in Southwest Queensland, the southern Blackall-Tambo and Longreach Regional Council areas of Central West Queensland. In New South Wales hopper bands are likely to develop from mid-February in the Brewarrina–Walgett–Carinda area and possibly the Bourke and Wanaaring districts. The location of further heavy rainfall will influence where egg laying occurs in early February in both states. There is the potential for a significant widespread swarm infestation affecting several states during autumn if heavy rainfall in early February results in further egg laying.
Surveys in New South Wales during January detected low density populations in most areas, but localised high density adults developed in parts of the Northwest Plains, Far West, Central West and Riverina in late January. Population density was low in the Central Highlands, South Central and Central West Queensland, but some swarm activity was reported in the Thargomindah, Tambo–Charleville, Longreach and Quilpie areas after mid-January.
Locust density is likely to have increased in parts of northern South Australia as a result of local egg laying during December and some possible low density immigration from Southwest Queensland during January. Further immigration is possible during the first half of February, which would establish a larger breeding population in parts of the Far North and Northeast regions.
The locust population level remained low in most of northern Victoria during January, but Department of Primary Industries surveys identified a persistent medium density adult population, including some late instar nymphs, in the Swan Hill area of Northwest Victoria.
| Location - NSW | Egg laying | Hatching | Mid-instar | Fledging |
|---|---|---|---|---|
| Brewarrina-Walgett | 31 January | 15 February | 25 February | 14 March |
| Bourke-Louth | 28 January | 13 February | 23 February | 14 January |
| Nyngan-Condobolin | 31 January | 16 February | 27 February | 17 March |
| Tobooburra-Wanaaring | 6 February | 20 February | 2 March | 18 March |
|
Location - Qld |
Egg laying | Hatching | Mid-instar | Fledging |
| Quilpie-Tambo | 20 January | 3 February | 13 February | 27 February |
| Thargomindah-Quilpie | 26 January | 8 February | 17 February | 4 March |
| Noccundra-Windorah | 4 February | 19 February | 28 February | 16 March |
| Longreach-Winton* | 22 January | 6 February | 18 February | 5 March |
| Quilpie-Tambo | 6 January | 20 January | 28 January | 12 February |
|
Location - SA |
Egg laying | Hatching | Mid-instar | Fledging |
| Moomba-Marree* | 6 February | 20 February | 2 March | 17 March |
| Yunta* | 10 January | 24 January | 1 February | 14 February |
| Oodnadatta-Marree* | 6 January | 19 January | 27 January | 9 February |
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 longterm 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.
Spur-throated Locust (Austracris guttulosa)
Nymphs from the initial egg laying of the current breeding season were detected in Southwest Queensland in early January and in the Central West in late January. The continued heavy rains throughout western Queensland and the Central Highlands in January will allow further breeding and the survival of nymphs already hatched. The likely outcome in terms of the overall size of the summer nymphal population and survival to fledging in autumn will be assessed after the current flood conditions subside in western Queensland to allow further surveys.
Surveys during January showed adult population densities remained at Isolated–Scattered density in Barcaldine and Blackall-Tambo Regional Council areas in Central West Queensland, but declined to Scattered–Numerous density in the Longreach area where higher densities were recorded in December. There were Isolated–Scattered density adults in the Central Highlands north of Emerald, in Murweh, Paroo and Balonne Shires of South Central Queensland and in South West Queensland. In New South Wales there were consistent Scattered density adults in the Bourke and Brewarrina districts, and occasional Isolated–Scattered density adults in the rest of the Far West and in the Northwest Plains. The light trap at Longreach caught high numbers of this species from 11 to 28 January and at Julia Creek throughout January.
Noticeable numbers of this species were also reported from the Far North region of South Australia during January and the light trap at Dulkaninna recorded low numbers of this species on several nights. Adults and some nymphs were reported from Alice Springs in mid-January.
Migratory Locust (Locusta migratoria)
Low numbers of adults of this species were detected west of Springsure in the Queensland Central Highlands during APLC survey in mid-January. Biosecurity Queensland identified Isolated density adults in the Emerald–Capella area of the Central Highlands in early January. Summer rains in this region could result in aggregation, egg laying and the possibility of localised gregarious populations developing.
2 February 2010