Incursion preparedness: anticipating the arrival of an economically important plant pathogen Xylella fastidiosa Wells (Proteobacteria: Xanthomonadaceae) and the insect vector Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) in Australia

Abstract

The glassy-winged sharpshooter, Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae), is an important insect vector of the xylem-limited plant pathogen Xylella fastidiosa Wells et al. that causes diseases in numerous plant species including food and feedstock crops, ornamentals and weeds. Both the pathogen and the vector are native to the Americas, and H. vitripennis has demonstrated high invasive ability but to date neither has been detected in Australia. The Australian wine grape, table grape, peach, plum, nectarine and citrus industries are particularly concerned about the arrival of X. fastidiosa and H. vitripennis because of the potential economic impact on these important commodities. Other commodity producers in Australia should also be concerned about this vector-pathogen, in particular the ornamental plant, avocado and olive industries. Past interceptions of H. vitripennis and the potential for X. fastidiosa to be moved in live plant material or within live vectors indicate the need for rapid detection of an incursion in areas considered at high risk. This requires identification of regions that have climatic and environmental conditions conducive to X. fastidiosa and H. vitripennis establishment as well as a detailed knowledge of their respective potential host plant ranges in new areas. These climatic regions and host plant species can then be targeted for monitoring in order to detect an incursion at an early stage. CLIMEX modelling has shown that much of coastal Australia has temperatures suitable for survival of both the vector and pathogen. A range of other requirements in addition to suitable climate must, however, be satisfied for an incursion to lead to establishment, proliferation and spread. This review article provides information that shows that the Australian environment is suitable for the establishment of H. vitripennis and that Australian native plant species are likely to serve as X. fastidiosa hosts and subsequent pathogen sources, and highlights future research directions.Key words alternative host, biosecurity, insect pest, pathogen transmission, Pierce's disease. Peroni et al. 2008) that causes disease in a wide range of economically significant agricultural plants. There are three key genotypes of the bacterium, each with a different host range, virulence and transmissibility (Schaad et al. 2004;Almeida et al. 2008;Nunney et al. 2010). The three genotypes that have been identified are X. fastidiosa subsp piercei, subsp. *anna.rathe@industry.nsw.gov.au bs_bs_banner Australian Journal of Entomology (2012) 51, 209-220

Distribution and Relative Abundance of Insect Vectors of Xylella fastidiosa in Olive Groves of the Iberian Peninsula

“…However, each pathosystem is peculiar, and requires precise characterization. Research on the biology, ecology and population density over time of ascertained and potential insect vectors is of paramount importance for setting up an effective and environmentally friendly bacterium-mediated disease control strategy [23,27]. The progressive expansion of infected areas by X. fastidiosa in Spain involving different key crops poses a serious risk to the agriculture of the Iberian Peninsula, especially olive growing, considering that Spain is the largest exporter of olive oil worldwide [11].…”

Genomic Insights into Xylella fastidiosa Interactions with Plant and Insect Hosts

“…Such efforts could have a significant impact on the eradication or management of X. fastidiosa introductions, as some biological knowledge would be already available to decision makers upon pathogen detection. Lastly, analysis of the potential threat of an introduction can provide important information to assess risk and develop science-based policies (e.g., Rathé et al 2012b).…”

Short communication. A survey of potential insect vectors of the plant pathogenic bacterium Xylella fastidiosa in three regions of Spain

“…The establishment and spread of X. fastidiosa in a new area depends on the presence of appropriate environmental conditions, host plants and vectors (Rathé et al, 2012). In a computer simulation program (CLIMEX) study concerning climatic conditions and possibilities of spread of X. fastidiosa, Hoddle (2004) concluded: "CLIMEX predicted that cold stress accumulation would exclude Pierce's disease-causing strains of X. fastidiosa from France and northern and central grape producing areas of Spain and Italy".…”