Current locust situation

The overall locust population remained at low-medium levels across inland eastern Australia with a moderate decrease in Central West and Riverina districts of New South Wales but slight increases in central Queensland during autumn. Routine ground survey was hampered by flooding from heavy rains during late March and early April. Surveys identified low-density adults remained in the Central West district of NSW with only occasional Low-Numerous adults detected, while in the adjacent Upper Western district more frequent low-density adults were encountered with some Low-Numerous adults identified. Some Numerous-density adults were identified in inland Queensland with frequent low-density adults present. Low-density nymphs were also identified in some surveyed areas. No more locust sightings were reported from NSW in autumn. No locust captures were recorded by any light traps in Dulkaninna of South Australia, Fowlers Gap and White Cliffs of NSW, and Thargomindah of Queensland for autumn. The UNSW insect monitoring radar in Hay was not in operation due to air-conditioning failure and likely antenna motor failure. No surveys were conducted in South Australia or Victoria, nor any locust reports received from these states during autumn.

Much of inland eastern Australia experienced a wet autumn due to the highest on record amount of rainfall from late March to early April when more than 200 mm rainfall were received by the Charleville-Quilpie-Windorah-Longreach areas with parts over 600 mm. However, much of the arid/semi-arid interior received below average to much below average amount of rainfall during April and May. Apart from these areas that received very high rainfall or downstream floods, most habitats in inland eastern Australia became unfavourable for locust breeding. Autumn temperatures were above average to highest on record (1–3 degrees warmer) over much of arid interior with a cooler April (down by two degrees below averages) over much of inland Queensland where excess rainfall was received. With the forecast for above average rainfall and warmer temperatures for winter, overwintering populations are likely to persist in favourable habitats.

The overall outlook is for low density populations across inland eastern Australia, with localised higher densities of nymphs developing possibly from overwintering eggs in parts of central west NSW and inland Queensland from September onwards. 

There is a low likelihood of widespread infestations developing in spring. 

The overall population increased slightly to low-medium levels in autumn across inland eastern Australia with a significant buildup in Central West Queensland. Early instars had been identified by survey up to early June, indicating an extended breeding season. Several Low-Density swarms were identified in the Muttaburra-Winton areas with consistent Numerous and Concentration-density adults detected. Some Numerous-density adults were also identified in the North West district of New South Wales. No capture in autumn was recorded by light traps in White Cliffs and Fowlers Gap of NSW, and Dulkaninna of South Australia except a few caught in early April in Thargomindah of Queensland. With heavy rainfall over much of inland Queensland during late March and early April and the forecast for above average rainfall with warmer temperatures for winter, habitat conditions should remain in favour for locust breeding. 

There is a moderate risk of a regional infestation in Central West Queensland. However, a widespread infestation is less likely to occur in winter and spring.

The population increased markedly in Central Highlands and Central West Queensland in autumn. Due to heavy rains, limited surveys conducted in New South Wales and South Australia did not identify any locusts in February. From early March, reports of locust bands were received from the Emerald-Alpha-Clermont areas where several bands were confirmed by survey and Low-Density swarms were identified in April. Some Scattered-density adults were also identified between Winton and Hughenden in April. In May, following further rainfall conducive for locust breeding more reports of locust sightings were received from the Muttaburra-Aramac areas where frequent locust bands and swarms were confirmed by survey. Under low night temperatures of autumn and winter, nocturnal long-range migration is unlikely but daytime short-distance dispersal can take locust adults tens of kilometres away in a warm day. Therefore, population dispersal and redistribution are likely to continue. The locust population in the Alpha area of Central Highlands declined over late autumn and no further reports of locust activities were received from this region. With the forecast above average rainfall and warm temperatures for winter, habitat conditions should remain in favour for locust survival, some breeding can occur where rainfall above 30 mm and some localised bands could develop from early to mid-September onwards. Some adult swarms may persist in the Muttaburra-Winton areas through September until spring rain results in breeding.

There is a moderate-high risk of a regional infestation developing in the Central West and a moderate risk in the Central Highlands during winter and spring.