Biol Invasions (2019) 21:1215–1225 https://doi.org/10.1007/s10530-018-1891-0 (0123456789().,-volV)(0123456789().,-volV) ORIGINAL PAPER Austropuccinia psidii on the move: survey based insights to its geographical distribution, host species, impacts and management in Australia Laura Fernandez Winzer . Katherine A. Berthon . Angus J. Carnegie . Geoff S. Pegg . Michelle R. Leishman Received: 23 July 2018 / Accepted: 27 November 2018 / Published online: 4 December 2018 Ó Springer Nature Switzerland AG 2018 Abstract Austropuccinia psidii is a plant fungus Myrtaceae species remains unknown, with no system- native to South and Central America which causes atic surveillance or monitoring program in Australia. myrtle rust disease, affecting the growth and repro- In order to better understand the extent of A. psidii duction of species in the Myrtaceae family. Austrop- geographic distribution and impacts on Australian uccinia psidii was first detected in Australia 8 years landscapes, a survey was sent to national park, ago in New South Wales. Since then it has spread botanical garden, local council, nursery and forestry rapidly along the east coast, and to date is known to agency employees in all states and territories where infect more than 375 native Myrtaceae species in the disease is known to be present. More than 500 Australia. Despite this, its rapid spread is not well surveys were sent, and 254 responses were received. documented and the potential threat to additional The survey confirms that A. psidii is widespread in New South Wales and Queensland urban environ- ments as well as in native vegetation communities. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10530-018-1891-0) con- Four new host species were confirmed, as well as four tains supplementary material, which is available to authorized new local government areas in two different states users. L. Fernandez Winzer (&) Á M. R. Leishman G. S. Pegg Department of Biological Sciences, Macquarie Department of Agriculture, Fisheries and Forestry, University, North Ryde, NSW 2109, Australia Horticulture and Forestry Science, Agri-Science e-mail: [email protected] Queensland, PO Box 267, Brisbane, QLD 4001, Australia L. Fernandez Winzer Á A. J. Carnegie Á G. S. Pegg G. S. Pegg Plant Biosecurity Cooperative Research Centre, Bruce, Forest Industries Research Centre, University of the ACT, Australia Sunshine Coast, Locked Bag 4, Maroochydore DC, QLD 4558, Australia K. A. Berthon RMIT University, Melbourne, Australia A. J. Carnegie Forest Health and Biosecurity, NSW Department of Primary Industries – Forestry, Parramatta, NSW, Australia 123 1216 L. Fernandez Winzer et al. reporting A. psidii infection. The disease severity was et al. 1998; Glen et al. 2007). Responses to infection classified as medium to high for most host species, are species-specific, with symptoms ranging from with especially negative impacts for Rhodamnia purple flecks in resistant species to characteristic rubescens and Rhodomyrtus psidioides. These survey yellow urediniospores that can lead to leaf distortion, results provide up-to-date information on the geo- defoliation, reduced reproduction (by infection of graphical distribution, host species and impacts of flowers and fruits) and death (Rayachhetry et al. 2001; A. psidii, which will assist in making management Uchida et al. 2006; Carnegie et al. 2016). Carnegie decisions relating to this pathogen across Australia. et al. (2016) assessed the impacts of A. psidii on two highly susceptible native species in Australia, brush Keywords Puccinia psidii Á Invasive species Á Plant turpentine (Rhodamnia rubescens) and native guava pathogen Á Myrtaceae (Rhodomyrtus psidioides). In these species, as a result of A. psidii infection, the canopy cover was signifi- cantly reduced by 76% and 95% respectively, with repeated damage causing mortality in 12% and 57% of Introduction these two species across their native range (Carnegie et al. 2016). Pegg et al. (2017) also reported significant Invasive plant pathogens pose a significant biodiver- levels of canopy damage and tree mortality in a range sity conservation challenge worldwide, with impacts of Myrtaceae species in moist rainforest ecosystems ranging from species- to ecosystem-level. Well known unique to Australia. It is clear that A. psidii is having examples include the fungus Cryphonectria parasitica severe impacts at the species-level, which may have that causes chestnut blight in North America (Anag- potential consequences at the ecosystem-level. nostakis 1987; Loo 2009) which has caused significant The dispersion of A. psidii occurs with spores being mortality of the American chestnuts (Castanea den- transported long distances by wind and animals, tata); and the soil-borne pathogen Phytophthora allowing it to spread easily (Uchida et al. 2006). The cinnamomi, which has not only altered the structure pathogen has spread to several countries and conti- of Eucalyptus forests in Western Australia (WA) but nents including North America (Florida, California also indirectly affected faunal species that rely on and Hawaii), southeast Asia (Japan, China, Indonesia affected forests for habitat in New South Wales and Signapore), South Africa, New Caledonia and (NSW) and Victoria (VIC) [e.g. Pseudomys fumeus more recently New Zealand (Marlatt and Kimbrough (smoky mouse) and Isoodon obesulus obesulus 1979; Kawanishi et al. 2009; Roux et al. 2013; Zhuang (southern brown bandicoot) (Cahill et al. 2008)]. and Wei 2011; DOC 2017; Soewarto et al. 2017). It Pathogens can be particularly destructive when they was first detected in Australia north of Sydney, NSW infect keystone species, as well as endemic, endan- in 2010, where it was first called myrtle rust (Carnegie gered or rare species, given their intrinsic value for et al. 2010). The rust is currently present along the east biodiversity conservation (Ellison et al. 2005; Loo coast of Australia with restricted distributions in VIC, 2009). Northern Territory (NT) and Tasmania (TAS) (Ber- Austropuccinia psidii is a pathogenic plant fungus thon et al. 2018), a distance of over 5000 km. The native to South and Central America that affects most recent expansion in distribution reported is Lord species in the Myrtaceae family (Coutinho et al. 1998; Howe Island, NSW (Kelly 2016). At present the only Glen et al. 2007). It causes a disease known as myrtle-, states where it has not been reported are South eucalyptus-, guava- or ohia rust, depending on the Australia (SA) and Western Australia (WA). species or group of species that it affects in different In order to effectively monitor the spread of countries. Myrtaceae is the dominant plant family in A. psidii and assess its impacts, we must first Australia (Wiltshire 2004), which is why the intro- determine which Myrtaceous species are susceptible. duction and spread of A. psidii is of particular concern As determined by laboratory based pathogenicity tests for Australian vegetation, including iconic Eucalyp- and field observations, at least 376 Australian Myrta- tus, Melaleuca and Leptospermum species. Austrop- ceous species are known to be susceptible to A. psidii uccinia psidii infects young growing tissues such as (Giblin and Carnegie 2014; Berthon et al. 2018; new leaves, tender shoots, flowers and fruits (Coutinho Makinson 2018; Berthon et al. unpublished data). 123 Austropuccinia psidii on the move 1217 However, the national host species list dates from contacts re-distributed the survey or published the link 2014 and there have been limited efforts to keep it in professional forums. updated. There is no systematic surveillance or The questionnaire comprised of a series of yes/no national program of monitoring the spread and impact questions with free responses following ‘yes’ answers, of A. psidii in Australia. Up-to-date information on the as well as adequate space for other comments. distribution and impacts of A. psidii is essential for Participants were asked to identify any species governments, scientists and natural resource managers infected by A. psidii they had seen, their location to make informed decisions for preventing further [locality name and local government area (LGA)] and introduction into new areas and managing existing the plant community type they occurred in. The list of affected plant communities. The aim of this study was LGAs which were reported to contain A. psidii was to investigate and collate information on the geo- collated and then mapped using the spatial analysis graphical and host range expansion of A. psidii and its software ArcMap 10.3 (ESRI 2012). These were then effects (infection severity) on newly reported suscep- compared with an updated dataset of myrtle rust tible hosts in four states and two territories in records (Berthon et al. 2018) to find LGAs which had Australia. In addition, our objective was to determine not previously been reported to contain A. psidii. The the current distribution range of A. psidii in Australia separation of plant community type into natural as well as quantifying its impacts and identifying the (rainforest, tall open forest, coastal woodland, ripar- control measures, if any, currently used to moderate ian/gully, swamp sclerophyll forest, dry sclerophyll these impacts. forest, and closed forest) and human mediated land- scapes (garden, street tree, plant nursery, botanical garden, and park) was made a posteriori for analysis Methods purposes. For this category, participants used a variety of terminologies,