The meadow spittlebug Philaenus spumarius is an epidemiologically relevant vector of the xylem-limited bacterium Xylella fastidiosa in all the European outbreaks described so far. Vector management through soil tillage and chemical control has so far yielded inconsistent results in terms of limiting bacterial spread, and alternatives are required. Metabolites released by endosymbionts of entomopathogenic nematodes (EPNs), such as Xenorhabdus spp. and Photorhabdus spp. are a promising alternative to pesticides for the control of several agricultural pests. While several studies have investigated direct toxicity exerted by endosymbiont metabolites, their sub-lethal (physiological and behavioral) effects and their impact on the transmission of vector-borne plant pathogens are largely unknown. Here we present preliminary data on the impact of EPN endosymbiont metabolites on P. spumarius in terms of i) direct toxicity of either EPNs or metabolites alone; ii) their effect on spittlebugs probing behaviors conducive to X. fastidiosa transmission, recorded using electropenetrography (EPG). Steinernema carpocapsae and Heterorhabditis bacteriophora were the species used for these trials. Topical exposure, artificial diet, and microinjection were tested as routes of exposure with a 72-hour survival assay. Apart from results, knowledge gaps and future perspectives for integrating EPNs into insect vector management plans are discussed.
Evaluation of toxicity against Philaenus spumarius of metabolites isolated from entomopathogenic nematodes (EPNs) symbionts.
Perfetto P.;Marra M.;Spadavecchia G.;Tarasco E.;Cornara D.
2025-01-01
Abstract
The meadow spittlebug Philaenus spumarius is an epidemiologically relevant vector of the xylem-limited bacterium Xylella fastidiosa in all the European outbreaks described so far. Vector management through soil tillage and chemical control has so far yielded inconsistent results in terms of limiting bacterial spread, and alternatives are required. Metabolites released by endosymbionts of entomopathogenic nematodes (EPNs), such as Xenorhabdus spp. and Photorhabdus spp. are a promising alternative to pesticides for the control of several agricultural pests. While several studies have investigated direct toxicity exerted by endosymbiont metabolites, their sub-lethal (physiological and behavioral) effects and their impact on the transmission of vector-borne plant pathogens are largely unknown. Here we present preliminary data on the impact of EPN endosymbiont metabolites on P. spumarius in terms of i) direct toxicity of either EPNs or metabolites alone; ii) their effect on spittlebugs probing behaviors conducive to X. fastidiosa transmission, recorded using electropenetrography (EPG). Steinernema carpocapsae and Heterorhabditis bacteriophora were the species used for these trials. Topical exposure, artificial diet, and microinjection were tested as routes of exposure with a 72-hour survival assay. Apart from results, knowledge gaps and future perspectives for integrating EPNs into insect vector management plans are discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
