Biological control of Acacia longifolia in Portugal
Acacia longifolia (Fabaceae) is native to Australia and was introduced into the EPPO region between the late 19th and early 20th centuries. Since its introduction in Portugal, the species has become one of the most widespread invasive species. It forms extensive populations within coastal ecosystems which act to displace native plant communities. Due to similar negative impacts recorded throughout its introduced range, the species has been the target of a classical biological control using the Australian gall-forming wasp Trichilogaster acaciaelongifoliae. The biocontrol agent has previously been successfully released in South Africa and it was released in Portugal in 2015. To predict the effectiveness of T. acaciaelongifoliae over a larger area, species distribution models were built for the plant and the biocontrol agent and the niche overlap was compared. Niches of both the invasive plant and the biocontrol agent were found to be highly similar through the introduction process. Distribution models identify suitable climatic areas for A. longifolia in 19% of the Mediterranean Basin and predict successful establishment of T. acaciaelongifoliae in 41% of the suitable area for A. longifolia. These results can quantify the risk of future A. longifolia invasion and potential success of biocontrol, as well as establish a comparative framework for similar programs being considered in other regions of the world dealing with A. longifolia invasions.
Sources
Dinis M, Vicente JR, César de Sá N, López-Núñez FA, Marchante E, Marchante H (2020) Can niche dynamics and distribution modelling predict the success of invasive species management using biocontrol? Insights from Acacia longifolia in Portugal. Frontiers in Ecology and Evolution, https://doi.org/10.3389/fevo.2020.576667