Locust Bulletin November 2009

The printed version of the Locust Bulletin is produced monthly during the spring-autumn period and includes a general summary for each major locust species, details of known distributions with regional forecasts, and maps of locust distributions and rainfall events. 

Locust Bulletin November 2009 - table of contents

General locust situation
Australian plague locust situation
Australian plague locust map October 2009
Forecast development dates
APLC aerial control Central West NSW
Rainfall October 2009
Terms and Abbreviations used in the Bulletin
Map of forecast districts used in the Bulletin
Map of forecast regions used in the Bulletin

General situation in October and outlook to mid-December 2009

Australian Plague Locust
Spur-throated Locust
Migratory Locust

The infestation in Central West New South Wales continued to develop during October and a number of swarms were reported in the Coonamble area at the end of the month. Hopper bands were identified in many parts of the Central West Livestock Health and Pest Authority (LHPA) throughout October, and in adjacent parts of Central North and Lachlan LHPA areas. Extended hatchings during September resulted in a range of nymphal stages and a proportion of fledgling adults from mid-October.  Landholders and LHPA staff continued ground control of hopper bands in the Collie–Quambone, Coonamble–Gulargambone–Baradine, Nyngan–Tottenham and Tullamore–Parkes areas. The APLC aerially controlled a total of 5,135 ha of bands in an area east and south of Coonamble in mid-October. Fledging will follow in November in the Parkes–Peak Hill area.

The outlook is for more swarms to form in the Coonamble–Gulargambone–Baradine, Quambone–Warren, Nyngan–Tottenham and Tullamore–Peak Hill areas during November. Migration of young adults from Central West New South Wales to other regions is likely during November and these could form swarms in some areas. Swarm density egg laying is likely in early November in areas which received heavy rainfall at the end of October. There is the potential for a second generation of nymphs in Central West NSW during December and of an expansion of the infestation area to other regions including the Northwest Plains and Central North of New South Wales and southern Queensland.

Surveys in western New South Wales indicated that dry conditions have resulted in some mortality of nymphs in the Ivanhoe–Menindee area and reduced the risk of a large infestation. However, there were small mid-instar bands in the Ivanhoe–Mossgiel area in mid-October. Band density nymphs were reported from one location in the Narrandera area of the Riverina in mid-October.

There was no significant population change in Queensland during October and no reports of activity of this species. Conditions remained dry in most regions and were unsuitable for locust breeding. Heavy rainfall at the end of October in the South Central and Darling Downs regions and storm rains in the Southwest will provide soil and vegetation conditions for a population increase. Significant immigration from New South Wales is possible during November.

No locust activity was reported from South Australia during October and vegetation was very dry in the Far Northeast region.  Rainfall in the Northeast and parts of the Northwest regions in the first half of October will provide suitable conditions for locust breeding and a small increase in population is possible.
Low numbers of adults and mid-instar nymphs were reported from the area around Echuca in North Central Victoria in mid-October.

In Western Australia nymphs were reported from many properties in the Central Agricultural region, including the Southern Cross, Merredin and Lake Grace areas during October. Nymphs were also reported from the Salmon Gums and Jerramungup areas in the Western Agricultural region.

•  Spur-throated locust                                                                               Austracris guttulosa

There were several reports of swarms in the Mt Isa area in Northwest Queensland during October. There were also swarms reported in the Winton, Dajarra, Richmond and Julia Creek areas during winter, and several reports of tree damage. The number of locusts caught in the Julia Creek light trap fell during October after high numbers during August and September. Surveys in September and October 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. There are also likely to be a number of swarms in the Queensland Gulf and parts of the Barkly Tableland at this time of year.  Adults will migrate and disperse to commence breeding from the start of the northern wet season. 

• Migratory locust    Locusta migratoria

There were no surveys in areas where this species is common during October. There were Isolated density adults in parts of the Central Highlands NSW Northwest LHPA during early spring.  Pasture conditions were generally dry in the Central Highlands and South Central Queensland, but with the seasonal rainfall expectation for these areas some localised breeding and population increase is possible during the forecast period.

2 November 2009

• Australian plague locust situation

  New South Wales
  Queensland
  Victoria
  South Australia

Distribution of Australian plague locusts: 1 October to 31 October 2009

Nymphal density

Present
Numerous - Subband
Band

Adult density

Nil - Isolated
Isolated - Scattered
Scattered - Numerous
Numerous - Concentration
Swarms present

Densities estimated for areas of locust habitat, based on survey and reports. 

Forecast development dates for indicative locations in NSW, Queensland and South Australia.

Location - NSW	Egg laying	Hatching	Mid-instar	Fledging
Coonamble-Collie	6 November	27 November	7 December	22 December
Coonamble-Quambone	5 June	15 September	27 September	20 October
Peak Hill-Parkes	24 March	30 September	15 October	5 November
Nyngan-Tullamore	11 November	2 December	12 December	27 December
Walgett-Goodooga	10 November	30 November	10 December	24 December
Narrabri - Wee-Waa	11 November	3 December	13 December	27 December
Location - Qld	Egg laying	Hatching	Mid-instar	Fledging
Cunnamulla-St George	11 November	27 November	7 December	21 December
Quilpie	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 assuming sufficient soil moisture for direct development. Development dates are estimated from 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.

 

Map of APLC control Central West NSW

NEW SOUTH WALES

Situation for October and forecast to mid-December 2009

Central West

Lachlan, Central West & Central North LHPA

Locusts and conditions

• There were widespread medium density nymphs throughout the Central West and northern Lachlan LHPA during October and many Bands in the Coonamble–Gulargambone-Baradine area. There was a small proportion of fledgling adults with these Bands from mid-October and by late October Concentration and swarm density young adults formed in several locations in that area. Swarms also began forming in the Warren–Trangie and Nyngan–Tullamore areas in late October. Fledging in the Parkes–Forbes area will follow in early November. Swarm formation will continue during November in the Central West LHPA and there is the possibility of egg laying from early November following heavy rains at the end of October.
  
  
• Aerial survey in early October identified mid-instar Bands covering a total area of 10,000 ha to the south and east of Coonamble, and there were many landholder reports of Bands on farmland. APLC carried out aerial control of Bands during 13–18 October. A total area of 5,135 ha was sprayed with fenitrothion insecticide.
  
  
• LHPA staff are continuing control and coordinating the issue of insecticide to landholders affected by high density nymphs. Ground control has been conducted in the Coonamble–Baradine, Quambone–Collie and Nyngan–Tullamore areas of Central West LHPA, the Warraumbungle–Tooraweenah area of Central North LHPA and the Parkes–Bogan Gate–Forbes area of Lachlan LHPA. By the end of October insecticide sufficient to treat over 20,000 ha had been distributed by Industry and Investment NSW for locust control.
  
  
• Locust reports from the Central West and northern Lachlan LHPA areas continued throughout October and by the end of the month Industry and Investment NSW had received over 300 locust reports.
  
  
• Surveys identified widespread Scattered–Concentration density young adults throughout the Central West LHPA during October. These adults were mostly immature, but some samples showed full egg development as early as mid-October.
  
  
• Survey through Central North LHPA in mid-October detected only Isolated–Scattered density adults in the Coonabarabran and Gunnedah districts.
  
  
• Survey in the Nyngan–Dandaloo area on 10 October identified Numerous–Band density third–fifth instar nymphs in some locations. In the Peak Hill–Tullamore area there were Numerous–Band density mid-Instar nymphs in several locations on 20 October and report numbers increased from this area in late October.
  
  
• In the Tottenham–Tullamore area of northern Lachlan LHPA there were Numerous–Concentration density adults in mid-October. There were still Present density nymphs at various stages in late October, but adult numbers appeared to have declined.
  
  
• There was light rainfall (<20 mm) in Central North LHPA and the eastern parts of the Central West and Lachlan LHPAs during the first two weeks of October.  Heavy storm rains (>40 mm) fell in the northern half of Central West LHPA during the last week of October, and light–moderate (<20–40 mm) falls in Lachlan and Central North LHPA. Pastures dried out during October, but rains at the end of the month will produce vegetation response in November.        

Forecast

• Cool and variable temperatures during late September and early October resulted in delayed nymphal development. Observations and reports during October continued to show a range of nymphal ages and a small proportion of fledglings in the Coonamble area. However, Bands identified from aerial survey in late September were predominantly at fourth and fifth instar by mid-October and these represented early September hatching. Late September hatchings are likely to be the result of eggs laid in late May and June, which would have bypassed diapause and completed development more slowly.  Some of the nymphs in late October may have been from eggs laid by adults present in September.
  
  
• Fledging began in mid-October in the Coonamble–Nyngan and will continue during the first half of November. Swarm formation began in late October and will continue throughout November.  Egg laying by swarms in the Coonamble–Nyngan area is likely in early November. The succession of generations could be less discrete if adults that developed in early September from over-wintering nymphs laid in any significant numbers during October.
  
  
• Fledging of the bulk of the population in the Peak Hill–Alectown area of Central West LHPA and the Tullamore–Trundle and Parkes–Forbes areas of Lachlan LHPA will begin in early November and a number of swarms could form in these areas.
  
  
• A proportion of the adults from the Central West are likely to migrate to other regions in NSW or southern Qld during November, and could potentially breed and lay eggs. The timing of major breeding events outside the Central West and Northwest LHPAs is likely to be influenced by rainfall in coming months.   

Risk(s)

• There is a risk of localised damage to crops from remaining nymphs and from swarms during November in the Central West and northern Lachlan LHPA.
  
  
• There is a high risk of egg laying in the Coonamble and Nyngan districts of the Central West LHPA during November and a second generation of nymphs emerging late in the month.
  
  
• There is a risk of migrations of adults from the Coonamble area expanding the area of infestation during November.   
  
  Landholder reporting of locust activity is important for organising control of a possible summer infestation in the Central West.

Riverina

Riverina & Hume LHPA

Locusts and conditions

• There was a report of localised Numerous–Band density nymphs in the Narrandera district in mid-October. APLC survey of the Riverina is planned for November.
  
  
• Nymphs ranging from third to fifth instar and forming small Bands on a property north of Binya were controlled by the landholder on 19 October.
  
  
• There were widespread light showers (<20 mm) during the first two weeks of October and further light falls during 25–31 October. Pastures remain mostly dry in the Riverina, but localised green areas remain in the southern parts of the region.
  

 Forecast

• The nymphs at Binya developed from sporadic autumn egg laying in the Narrandera area. There may have been other nymphs in the Narrandera district during October, which would have fledged by early November and could produce an increase in adult numbers to medium density.
  
  
• There is the potential for immigration of adults from the Central West LHPA during November.  

Risk(s)

• There is a moderate risk of immigration from the large population in the Central West during November.

Northwest Slopes and Plains

Northwest LHPA

Locusts and conditions

• The population in the Come-By-Chance area the southern Walgett district declined during October after control by landholders and LHPA staff. Surveys in the Narrabri, Moree and Walgett districts detected only low density adults in most areas.
  
  
•  Survey in mid-October identified Isolated–Scatted density adults and Numerous mid and late instar nymphs in the Hollywood–Brantwood area, southeast of Come-By-Chance.
  
  
• There were consistent Isolated–Scattered density adults in parts of Narrabri, Moree and Walgett districts on 10–11 October and occasional early instar nymphs in the Mungindi area.
  
  
• Widespread light rains (<20 mm) fell in the Narrabri district during the first week of October. In the last week there were heavy falls (>40 mm) in the Walgett and Narrabri districts and light–moderate falls in the Moree and Northern Slopes districts. Pastures will respond in November in areas which received heavy rains.

Forecast

• The infestation south of Come-By-Chance area declined as a result of control of nymphs in September, the drying of pastures and the fledging of remaining nymphs and movement of adults in early October.
  
  
• Immigration of locusts from the Central West is likely during November, which could produce a significant population increase and breeding in this region after widespread rains in late October. Breeding in early November could produce nymphs from late in the month. If swarm density immigration occurs a summer infestation could result.

Risk(s) 

• There is a high probability of some immigration of locusts from Central West LHPA during November, with a subsequent risk of significant breeding in parts of the Northwest LHPA.  

Far West

Darling & Western LHPA

Locusts and conditions

• Limited survey was conducted in the Brewarrina and Bourke districts in October. Locust population density remained at Scattered–Numerous level in Darling LHPA.
  
  
• No significant locust catches were recorded in the Fowlers Gap or White Cliffs light traps during October.
  
  
• There was widespread light–moderate rainfall (<20-40 mm) in the Cobar, Bourke, Brewarrina and Wanaaring districts in the last week of October, and some localised pasture response will occur in early November.

Forecast

• Remaining nymphs in the Bourke–Tilpa area in September would have fledged by October and are likely to have maintained a Scattered–Numerous density adult population in the Bourke district.
  

• There is potential for immigration into the Darling LHPA from the Central West during November. If significant immigration occurs in early November, high density egg laying could occur in the Brewarrina and Bourke districts.
  

• Rainfall in the Brewarrina, Bourke and Wanaaring districts at the end of October will produce suitable conditions for breeding and egg laying by resident or immigrant locusts during early November.
  

• The continuing very dry conditions in northern Western LHPA are unfavourable for egg laying by immigrants. Moderate–heavy rainfall during the forecast period could result in egg laying by immigrants.

Risk(s)

• There is a moderate risk of some immigration of locusts from Central West NSW during November and of egg laying in the Brewarrina and Bourke districts.   

Far South West

Western LHPA

Locusts and conditions

• Survey in October indicated a decline of the nymph population in the Ivanhoe–Menindee area as a result of dry pasture conditions, but there were a number of small Bands in the Ivanhoe–Mossgiel area.
  
  
• Survey in mid-October detected Numerous density third and fourth instar nymphs at several locations around Gum lake and Dalmorino in the Ivanhoe–Menindee area, but there were some small Bands of third instar nymphs in localised greener vegetation areas. There were still small third and fourth instar Bands in the Lignum Park area to the south of Ivanhoe.
  
  
• There were patchy light showers (<20 mm) in the Balranald–Wentworth district during the first week of October and further widespread light showers during the last week of the month. Pasture conditions remain dry in most areas.

Forecast 

• The development rate of nymphs in the Ivanhoe–Menindee area appears to have been slowed as a result of limited moisture availability in the dry conditions.
  
  
• Fledging of surviving nymphs in the Ivanhoe area will have begun in late October which is likely to produce and an overall increase in adult population to Numerous density and possibly some localised Concentrations in early November.  

Risk(s)

• An increase in adult population density to Numerous density is likely in the Ivanhoe area in November after fledging of nymphs in the district.

All locust activity should be reported to your Livestock Health and Pest Authority or Primary Industries, Industry & Investment NSW.
A toll-free call to the APLC can be made on 1800 635 962. An answering machine is attached for after-hours calls.

 

QUEENSLAND

Situation for October and forecast to mid-December 2009

Southwest

Barcoo, Bulloo, Quilpie & Diamantina Shire

Locusts and conditions

•  This region was not surveyed during October and there were no reports of locust activity. Population density is expected to have remained low in this region.
  
  
• The Nooyeah Downs and Birdsville light traps recorded no locusts during October.
  
  
• There was light rainfall (<20 mm) in Quilpie and eastern Bulloo Shires, along with some local heavy storms (>40 mm) around Quilpie during the last week of October. Pasture vegetation is very dry in most areas.  

Forecast

• The current dry conditions in this region are unsuitable for locust breeding and there was unlikely to have been any significant local population development during October.
  
  
• Rainfall in eastern Bulloo and part of Quilpie Shire at the end of October will produce suitable soil and vegetation conditions for breeding and egg laying in early November.
  
  
• With the seasonal expectation of storm rains in this region in November–December, suitable conditions could allow breeding and egg laying in some areas. If significant immigration occurs during November a large population increase could result.
  
  
• There is potential for significant immigration from NSW during November.
  
  
• Widespread moderate–heavy rainfall during the forecast period could allow egg laying by resident and immigrant locusts and result in a significant population increase.

Risk(s)

• There is a moderate risk of a population increase as a result of immigration or local population breeding in early November in the Quilpie and eastern Bulloo Shire.

Locust activity should be reported to Biosecurity Queensland (Queensland Primary Industries and Fisheries). A toll free call to the APLC can be made on 1800 635 962. An answering machine is attached for after-hours calls.

Central West and Northwest

Longreach, Barcaldine and Blackall-Tambo Regional Shire. Boulia, Cloncurry, Flinders, Mckinlay, Mt Isa, Richmond & Winton Shire

Locusts and conditions  

• Limited survey was conducted in part of the Blackall-Tambo Regional Council area during October. Only Isolated density adults were detected in the area south of Tambo and Present density second and fourth instar nymphs.
  

• No locusts of this species were caught in the Longreach or Julia Creek light trap during October.
  

• There was isolated light rainfall (<20 mm) in the Tambo area during 9–16 October and more widespread light rains in the Central West during the last week, along with some heavy storm rains (>40 mm) in part of the Barcaldine Regional Council area. Vegetation is dry on most areas. 

Forecast

• Nymphs in the Tambo area indicate some low level breeding in the area in late September. Significant egg laying in the region likely to be dependent on rainfall during November.
  
  
• There is the potential for some immigration from NSW during November.

Risk(s)

• An increase in population density is possible during November as result of local development or immigration.

Central Highlands

Central Highlands and Isaac Regional Council

Locusts and conditions

• No survey was conducted in this region during October and there were no reports of locust activity. Population density is expected to have remained low.
  

• There was patchy, mostly light (<20 mm), rainfall in the Central Highlands and western Isaac Regional Council areas during the last week of October. Pastures remain dry in most areas.

Forecast   

• Given the very low population level in the region, there is unlikely to be a large increase in population during November or December.  

Risk(s)

• No significant risks are identified for this region during the forecast period.        

South Central Queensland and Darling Downs

Balonne, Murweh and Paroo Shire. Roma, Dalby and Goondiwindi Regional Council

Locusts and conditions

• Limited survey in October identified a low density population in Paroo and Murweh Shires.
  
  
• Survey detected Isolated density adults in the Cunnamulla and Augathella areas in mid-October.
  
  
• There was heavy rainfall (>40 mm) in Paroo during 25–31 October, along with light–moderate (20–40 mm) falls in Murweh and Balonne Shires, and Roma and Regional Council area. There were light falls on the Darling Downs at that time. Pasture vegetation will respond to rainfall in Paroo Shire in November.

 

Forecast

• Heavy rainfall in late October will produce suitable soil and vegetation conditions for locust breeding and egg laying by local and immigrant locusts.
  
  
• There is a potential for significant immigration of adults from NSW during November.   

Risk(s)

• There is a moderate risk of immigration from NSW during November, resulting in possible high density egg laying in parts of Paroo, Balonne and Murweh Shires.   
              

Locust activity should be reported to Biosecurity Queensland (Primary Industries & Fisheries). A toll free call to the APLC can be made on 1800 635 962. An answering machine is attached for after-hours calls.

VICTORIA

Situation for October and forecast to mid-December 2009

Locusts and conditions

• Surveys by DPI Victoria in the second half of October identified occasional adult locusts in areas east and west of Echuca. There were present density second and third instar nymphs at locations near Patho, Strathallan and Lockington.
  
  
• There were patchy light showers (<20 mm) in northern Victoria during the first two weeks of October and further light falls during 25–31 October. Pastures are drying off in many areas.              

Forecast

• Nymphs from spring hatchings would fledge in early November and may contribute to a general low adult population density. Conditions for breeding will be dependent on further rainfall.
  
  
• There is a potential for some immigration into Victoria during November.

Risk(s)

• The current very low density population are unlikely to pose a threat to agriculture.
  
  
• There is a low risk of immigration from NSW during November.          

Locust activity should be reported to the Department of Primary Industries, Victoria. A toll-free call to the APLC can be made on 1800 635 962. An answering machine is attached for after-hours calls. 

SOUTH AUSTRALIA

Situation for October and forecast to mid-December 2009

Far North, Northwest, Northeast & Western Agricultural region

Locusts and conditions

• Survey was not conducted during October and there were no reports of locust activity.
  
  
• The Dulkaninna and Oodnadatta light traps recorded no locust activity during October.
  
  
• There was light–moderate rainfall (20–40 mm) in the Flinders Ranges area of the Northeast region during the second and third weeks of October. Parts of the Northwest region received light falls (<20 mm) during 9-16 October. 
          

Forecast

• Conditions remain unfavourable for locusts in the Far North region, while in the Northeast, Murray Valley and Western Agricultural regions there were suitable conditions for some breeding. An increase in population from very low levels is possible as a result of breeding during October.     

Risk(s)

• A small population increase is possible in parts of the Northwest, Northeast or Western Agricultural regions.

Locust activity should be reported to Primary Industries & Resources, South Australia.
A toll-free call to the APLC can be made on 1800 635 962. An answering machine is attached for after-hours calls.

Map of Rainfall distribution 

 

Place Name Key for Rainfall Distribution Map

Queensland		Northern Territory		New South Wales
Bo	Boulia	AS	Alice Springs	B	Bourke
Br	Brisbane	TC	Tennant Creek	BH	Broken Hill
Bi	Birdsville			Du	Dubbo
Ch	Charleville	South Australia		Ha	Hay
CT	Charters Towers	Ad	Adelaide	Iv	Ivanhoe
Em	Emerald	CP	Coober Pedy	Na	Narrabri
Hu	Hughenden	Ma	Marree	Sy	Sydney
JC	Julia Creek	Oo	Oodnadatta	Ti	Tibooburra
LH	Lawn Hill	PA	Port Augusta	Wy	West Wyalong
Lo	Longreach	Yu	Yunta
No	Normanton
Qu	Quilpie	Victoria
SG	St. George	Ho	Horsham
Ur	Urandangi	Me	Melbourne
Wi	Windorah	Mi	Mildura

Glossary of terms and abbreviations used in the Locust Bulletin

Where higher densities occur a large proportion of the regional population is concentrated in small areas with lower densities elsewhere, so the high densities cannot be extrapolated across the area of an entire region. Typically a range of density classes is found within surveyed regions and higher densities occur where habitat conditions are favourable. More detail is available about terms and descriptions used here.

Nymph Densities	Number per m2
Present (P)	1        -    5
Numerous (Num)	6        -    30
Sub-band (SB)	31      -    80
Band (B)	>   80
Adult Densities	Number per m2	Number per hectare
Isolated (Iso)	-    0.02	< 200
Scattered (Scat)	0.03   -    0.1	>200   -   1000
Numerous (Num)	0.2     -    0.5	>1000  -  5000
Concentration (Conc)	0.6     -    3.0	>5000  -  30,000
Low Density Swarm (LDS)	4.0     -    10	>30,000 - 100,000
Medium Density Swarm (MDS)	11      -    50	>100,000 - 500,000
High Density Swarm (HDS)	>   50	>500,000
General Density Classes	Nymph Densities	Adult Densities
very low, occasional	Nil-Present	Nil-Isolated
low	Present-Numerous	Isolated-Scattered
medium	Numerous-Subband	Scattered-Numerous
high	Bands	Concentration-Swarms

Reporting locust infestations

It is important that all locust activity is reported as soon as possible to your Department of Primary Industries (Agriculture) or to the Australian Plague Locust Commission.

State	Authority to report locust infestations to
New South Wales	Livestock Health and Pest Authority (LHPA) or Primary Industries, Industry & Investment NSW
Queensland	Biosecurity Queensland, Queensland Primary Industries & Fisheries
South Australia	Primary Industries & Resources South Australia (PIRSA) Plant Health
Victoria	Department of Primary Industries, Victoria - Plague Locust information

Reports to the Australian Plague Locust Commission can be made by:

Free call (Canberra) - 1800 635 962 (24 hours)
Fax (Canberra) - (02) 6272 5074
Email: Locust Report

 

Forecasting Districts used in the Bulletin

General regions referred to in the Bulletin

Location of APLC light traps (black circles).
Locust habitat areas shaded.