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 use of a multidisciplinary approach is becoming increasingly important when developing management strategies that mitigate the economic and biological costs associated with invasive pests. A framework of simulated dispersal is combined with life-history information and analyses of population genetic structure to investigate the invasion dynamics of a plant disease vector, the island sugarcane planthopper (Eumetopina flavipes), through an archipelago of significant Australian quarantine concern. Analysis of eight microsatellite loci from 648 individuals suggests that frequent, wind-assisted immigration from multiple sources in Papua New Guinea contributes significantly to repeated colonization of far northern islands. However, intermittent wind-assisted immigration better explains patterns of genetic diversity and structure in the southern islands and on the tip of mainland Australia. Significant population structuring associated with the presence of clusters of highly related individuals results from breeding in-situ following colonization, with little postestablishment movement. Results also suggest that less important secondary movements occur between islands; these appear to be human mediated and restricted by quarantine zones. Control of the planthopper may be very difficult on islands close to Papua New Guinea given the apparent propensity for multiple invasion, but may be achievable further south where local populations appear highly independent and isolated.

Larvae of the native Australian chrysopid Mallada signata use discarded prey items and environmental debris ('trash'), carried on the dorsal abdominal segments, as camouflage. Larvae that carry trash were confirmed experimentally to experience lower rates of cannibalism, an effect attributed to the camouflage conferred by the package. Larvae preferred physically hard material over normal dietary items when constructing their trash-package. The inclusion of these materials in the package may provide both physical and chemical camouflage from predator and prey alike. When encounter rates between conspecifics were low, larvae that carried trash increased their activity rates as they aged. In contrast, trash-denuded larvae decreased activity rates as they aged. Among first-instar larvae, as the density of larvae increased and encounters became more frequent, those with trash moved further than those without. Larvae with trash packages exhibited lower cannibalism and higher activity rates, which may subsequently enhance foraging capacity.