Most likely, Xylella fastidiosa established in Europe through infected ornamental plants, with a successive spillover to cultivated ones. After the first detection in Europe on olive trees, Xf has detected on both cultivated and ornamental species. Understanding the spillover between the two plant typologies is critical in terms of pest spread patterns and the grasp of potential risk of infection associated with vegetal species with different functions.
Given its polyphagy and wide distribution, the meadow spittlebug Philaenus spumarius, the principal Xf vector in Europe so far, might play an essential role in such a spillover. Researchers combined and analyzed spittlebug’s behavioral data to infer possible bacterium patterns of spread. More specifically, they selected oleander and rosemary as potential introductory hosts and grapevine and cherry as economically important threatened plants in order to reveal host plant feeding preferences.
The data collected suggest that, in Europe, cultivated plants as grapevine and cherry could be more relevant than oleander and rosemary as Xf sources for the vector. In this scenario, we might have a three-stages spillover, with P. spumarius acquiring the bacterium while feeding from infected cultivated plants, then first spreading it within cultivated orchards, and successively to ornamental plants during its dispersal. Studies of the behaviour of other potential vector species that could play a role for the inital spillover of Xf from ornamentals to cultivated plants, are ongoing.
DOI: https://doi.org/10.1127/entomologia/2019/0841 | via Schweizerbart.