The introduction of novel bluetongue serotypes and genotypes into northern Australia is considered possible via the long-distance windborne dispersal of Culicoides (Diptera: Ceratopogonidae) vectors from Southeast Asia. Initial findings from simulation modelling of potential dispersal over a 15-year period revealed that the greatest risk for incursion of windborne Culicoides from the island of Timor into northern Australia occurs during December-March. The regions at greatest risk for incursion include the top end of the Northern Territory and the Kimberley region in Western Australia, but there is potential for more widespread dispersal into northern Australia based on Timor as the putative source. The establishment of a more pathogenic strain of the virus, or of a novel Culicoides vector introduced by such inter-continental dispersal events, could dramatically alter Australia's current bluetongue disease status.

Summary 1. The identification of dispersal mechanisms which facilitate particular biological invasions is paramount for the successful management of invasive species. If the dispersal mechanism promotes high propagule pressure, the probability of successful establishment and spread is enhanced. 2. Invasive species may enter mainland Australia from Papua New Guinea via the Torres Strait islands, and their dispersal through the region may be assisted by wind. The island sugarcane planthopper Eumetopina flavipes is of particular concern to Australian quarantine authorities. Long‐distance, wind‐assisted immigration from Papua New Guinea may be responsible for the continued presence of E. flavipes in the Torres Strait islands and on the tip of mainland Australia. Simulation was used to predict E. flavipes wind‐assisted migration potential from Papua New Guinea into the Torres Strait islands and mainland Australia. Field studies were used to test the predictions. 3. Wind‐assisted immigration from Papua New Guinea was predicted to occur widely throughout the Torres Strait islands and the tip of mainland Australia, especially in the presence of tropical depressions and cyclones. Simulation showed potential for a definite, seasonal immigration which reflected variation in the onset, length and cessation of the summer monsoon. 4. In general, simulation predictions did not explain E. flavipes observed infestations. The discrepancy suggests that post‐colonization processes such as the temporal and spatial availability of host may be equally or more important than possible wind‐assisted immigration in determining population establishment, persistence and viability. 5. Despite the potential for wide‐spread, annual immigration throughout the Torres Strait islands and the tip of mainland Australia, E. flavipes control may be possible by managing the cultivation of host plants on an ongoing annual basis to avoid recolonization, especially prior to or during critical immigration periods. 6. Synthesis and applications. Wind may promote significant incursions of E. flavipes from Papua New Guinea into northern Australia. Management strategies should consider the relative importance of both pre‐ and post‐invasion processes in determining establishment success, so that response measures can be implemented at the appropriate stage of invasion. In this way, successful control may be enhanced, serving to reduce the overall cost of invasion.

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The Australian Plague Locust Commission (APLC) is responsible for the monitoring and control of locust populations that pose a threat to agriculture in the inland areas of four Australian States, a total area of 2 million km2. A GIS‐based decision support system (DSS) is used to co‐ordinate the collection, processing, analysis and display of a range of spatial data for the forecasting of locust population development and to assist control operations. The resultant forecasts are used to help locate population aggregations early in a breeding sequence so as to enable effective preventive control. The data collection components of the DSS include wireless direct transfer of locust survey data from the field and daily internet collections of weather data. Locust distribution and age information is collected by APLC officers on regular vehicle surveys using GPS‐connected palmtop computers, and sent directly to a GIS server via high frequency (HF) radio modems. Locust reports from landholders and state extension staff are also incorporated into the system. The current survey data are used to estimate broad distributions, and to seed spatially‐explicit development models that can identify the timing of life stages that can be effectively managed. Information on the distribution of rainfall, temperature and wind‐fields is collected automatically from the internet and integrated with habitat information and locust distributions. Online weather data products from the Bureau of Meterology are also accessed regularly to assist in operational decision making.

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