The fungal community associated with the ambrosia beetle Xylosandrus compactus invading the mediterranean maquis in central Italy reveals high biodiversity and suggests environmental acquisitions

In summer 2016 a severe infestation of the alien ambrosia beetle Xylosandrus compactus was recorded from Mediterranean maquis in Circeo National Park Central Italy. Trees and shrubs were infested displayed wilting necrosis terminal branches caused by combined impact insect associated pathogenic fungi. A preliminary screening carried out on captured adults resulted isolation discrete number fungal taxa with different life strategies, ranging true mutualist (e.g. Ambrosiella xylebori) to plant pathogens (Fusarium spp.). present study, high-throughput sequencing applied determine total diversity functionality community X. collected galleries three woody hosts, Quercus ilex, Laurus nobilis, Ceratonia siliqua. The effect season host determining composition investigated. 206 OTUs composed compactus. Eighteen shared among including A. xylebori members Fusarium solani complex. All but two previously beetles. Sixty-nine resolved species level, identifying 60 species, 22 which already reported literature as beetles or other insects. Functional guild assigned most saprotrophs pathogens. Effects seasonality assemblage highlighted suggesting acquisition new during invasion process. consequences enriched risk insurgence novel threatful insect–fungus association are discussed considering direct indirect effects invaded habitat.