Australian Plague Locust (Chortoicetes terminifera)
Locust populations were at low levels across inland eastern Australia with some localised small bands developing mainly in the Nyngan and surrounding areas of New South Wales since September 2024. Surveys conducted since early August did not identify any hopper bands in the Innamincka and surrounding areas where a large adult population formed during last autumn. Overwintering egg beds were discovered in the Girilambone-Nyngan-Nevertire areas and embryo development was closely monitored during winter. More than two dozen small hopper bands (some up to 300m long) have been identified in the Girilambone-Warren-Nevertire areas in September, with some visible from the air. Several small bands were also identified in the Broken Hill area in mid-September. Low-density nymphs and adults were identified by surveys in other parts of inland eastern Australia. Apart from several large catches of grasshoppers in late September by the light trap in Dulkaninna of South Australia, only a few locusts have been caught by light traps in Thargomindah of Queensland so far. No reports from other areas except those from the Nyngan and Broken Hill areas.
The inland eastern Australia received up to 25 mm of rainfall for September with less than 10 mm of rainfall over the arid interior, at average to very much below average levels historically, while October rainfall totals were slightly higher with some parts receiving over 100 mm of rainfall but again with less than 10 mm of rainfall over the arid interior, generally at average to below average levels. Although some heavy rains fell over the arid/semi-arid interior during late June to early July, locust habitat conditions were generally poor across inland eastern Australia by early spring. Winter temperatures over inland eastern Australia were 1–3 degrees above averages, largely attributed to the much warmer August. September temperatures continued the warm trend and October temperatures were 1–4 degrees above averages. Habitat conditions have generally been unfavourable this spring for further locust breeding and are likely to remain unfavourable over much of inland eastern Australia for the next three months with forecasts slightly above average rainfall but warmer temperatures and the absence of La Niña event developing.
The overall outlook is for low-density populations across inland eastern Australia, with localised medium to high densities of spring population nymphs and adults developing in Central West and Western districts of NSW. It is unlikely that any large bands or swarms will develop until January 2025, nor are any significant migrations likely to occur.
There is a very low likelihood of widespread infestations developing between now and early summer.
Spur-throated Locust (Austracris guttulosa)The overall population was at low levels across inland eastern Australia with some medium-density populations present in the arid interior. Surveys from early August to late October identified widespread Isolated to Scattered-density adults with some Numerous-density adults present mainly in the Channel Country of Queensland. No captures were recorded on the light traps at Dulkaninna (SA), White Cliffs (NSW) and Fowlers Gaps (NSW), but a few catches made by the light trap at Nooyeah Downs (Queensland) in late September. No nymphs were identified by survey, but some adults were caught with near-fully developed eggs in the Nyngan area of NSW in mid-October, indicating overwintering mature adults may have already undergone early breeding. Habitat conditions continue to remain unfavourable over much of inland eastern Australia, but some localised breeding is likely under favourable habitats.
There is a low risk of a widespread infestation. Though, some localised breeding is possible to occur in favourable habitats of tropical and sub-tropical Queensland between now and January 2025.
Migratory Locust (Locusta migratoria)The overall population was at very low levels across inland eastern Australia. Some adults were identified in the Central Highlands of Queensland and surrounding areas by survey in addition to an individual found in the Nyngan area of NSW. Limited localised breeding is likely under favourable habitats, but high-density populations are unlikely to result from the current very low background population levels.
There is a very low risk of a widespread infestation developing during between now and January 2025.
07 November 2024
(online version available soon)
It is important that any locust activity be reported as soon as possible to your local biosecurity authority, primary industries department or to the commission. A toll-free call to the APLC hotline can be made on 1800 635 962. An answering machine is attached to this phone for after-hours calls. Reports can also be emailed to APLC via aplc@agriculture.gov.au or made through the website at https://www.agriculture.gov.au/pests-diseases-weeds/locusts/landholders/reporting_locusts.
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