Climate tolerances of Philaenus spumarius should be considered in risk assessment of disease outbreaks related to Xylella fastidiosa
The bacterium Xylella fastidiosa (Xf) is an invasive insect-borne pathogen, which causes lethal diseases to important crops including olives, citrus, almonds and grapes as well as numerous forest, ornamental, and uncultivated plants. Outbreaks of Xf-related plant diseases are currently occurring in the Mediterranean region, causing substantial losses to various agricultural sectors. Several models have recently been published to identify which regions are at highest risk in Europe; however, such models did not consider the insect vectors, which constitute the key driver of short-range Xf spread. We fitted bioclimatic species distribution models to depict the macroclimatic preferences of the meadow spittlebug Philaenus spumarius L. (1978) (Hemiptera: Aphrophoridae), the major epidemiologically relevant vector currently responsible for Xf spread in the Europe. Many regions of Western Europe and Mediterranean basin are predicted by models as highly climatically suitable for this vector, including all regions where severe Xf have occurred so far. Conversely, the driest and warmest areas of the Mediterranean basin are predicted as little suitable for P. spumarius. Models forecast that agricultural-important parts of the southern Mediterranean area might experience a substantial decrease in climatic suitability for P. spumarius by the period 2040–2060. Areas predicted as highly suitable just for the bacterium but not optimal for this vector are apparently still free of severe Xf outbreaks, suggesting that climate tolerances of P. spumarius might partly explain the current spatial pattern of Xf outbreaks in Europe and should always be considered in further risk assessments. ; Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work has been financially supported by the Spanish Ministerio de Ciencia, Innovación y Universidades, Grant/Award Number: AGL2017-89604-R and the European Union Horizon 2020 research and innovation program under grant agreements no. 635646 POnTE (Pest Organisms Threatening Europe), and no. 727987 XF-ACTORS (Xylella Fastidiosa Active Containment Through a multidisciplinary-Oriented Research Strategy). The first author of this study was funded by the fellowship "Ayudas destinadas a la atracción de talento investigador de la Comunidad de Madrid". Daniele Cornara participation in this work was supported by a research grant in the frame of European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 835732 XYL-SPIT.