Biological control strategies for Xylella fastidiosa
Xylella fastidiosa (EPPO A2 List) is a xylem-limited bacterium that is transmitted by xylem-fluid feeding insects. Biological control methods have the potential to (1) limit or control the bacterium in the host and (2) to control the insect vectors of X. fastidiosa. Some research has been undertaken to evaluate biological control of the bacterium where it has been shown that some endophytic species can reduce the virulence of X. fastidiosa in the host, by competing with the pathogen for niche availability or through the production of compounds that effect its pathogenicity. However, in general, the efficacy of endophytic candidates is inconsistent across different host plant species and environmental conditions. For the biological control of X. fastidiosa vectors, predatory insect species such as Zelus renardii (Hemiptera: Reduviidae) have been shown to reduce Philaenus spumarius (Hemiptera: Aphrophoridae) populations which in turn has been shown to reduce the incidence of X. fastidiosa in olive trees. Fungal pathogens such as Akanthomyces muscarius (Hypocreales) and Beauveria bassiana (Hypocreales) are effective against P. spumarius. Egg parasitoids such as Gonatocerus spp. (Hymenoptera) have been shown to reduce vector populations by up to 95% following their release. Research into the biological control of X. fastidiosa and integration of this with other management practices is ongoing in the EPPO region.
Sources
Mourou M, Incampo G, Carlucci M, Salamone D, Pollastro S, Faretra F, Nigro F (2025) Insight into biological strategies and main challenges to control the phytopathogenic bacterium Xylella fastidiosa. Frontiers in Plant Science 16, 1608687. https://doi.org/10.3389/fpls.2025.1608687