Jessica L. Hoskins

Russian wheat aphid (Diuraphis noxia, Mordvilko ex Kurdjumov) (RWA) is a major pest of wheat and barley. Although rice (Oryza sativa L.) is not considered a primary host, RWA has been found on drill-sown rice in Australia prior to the application of permanent water. This study investigates the persistence of RWA on rice and evaluates plant responses to infestation, with the aim of determining whether pest management interventions are justified in Australian rice-growing systems. A series of replicated glasshouse trials was conducted using single and repeated aphid infestation pressures. Results demonstrate that rice is an unsuitable host for RWA, with aphid populations declining over time in all treatments, suggesting that rice does not support self-sustaining populations. A single infestation caused no measurable injury to rice, while repeated infestations led to only minor physiological effects, with plants recovering rapidly after aphid removal. These findings indicate that RWA does not pose a direct threat to rice production in Australia under current farming practices and that the routine application of insecticides for its control in rice is not justified.

Exotic tephritid incursions are of high concern to Australia’s biosecurity and its horticultural industries. It is vital that Australia remains ready to respond to incursions as they arise, as an incursion of tephritid fruit fly species will result in significant economic losses. In this review, we compared Australian incursion management strategies for fruit flies with global management strategies and identified possible areas where improvements could be made in an Australian context. Overall, Australia has a good understanding of the main tephritid threats, of which Bactrocera species from across the Torres Strait (northern Australia) are of most concern. Effective tools for tephritid detection and early warning surveillance at points of entry are in place at ports and in horticultural areas Australia-wide and provide the basis for initiating biosecurity responses in the event of an incursion. Area-wide control measures used in successful eradication attempts globally are available for use in Australia. However, a specific tephritid emergency response plan identifying suitable response measures and control options for species of concern is not yet available. We have identified that Australia has the policies and management tools available to respond to an exotic tephritid incursion, but the speed at which this could be accomplished would be greatly improved by the development of species-specific emergency response plans.