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

中文翻译：

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与入侵意大利中部地中海马基斯的豚草甲虫 Xylosandrus compactus 相关的真菌群落显示出高度的生物多样性并建议进行环境收购

2016 年夏天，在意大利中部的 Circeo 国家公园的地中海马基斯记录到了外来金花甲虫 Xylosandrus compactus 的严重感染。由于昆虫和相关病原真菌的共同影响，树木和灌木受到侵染，并表现出枯萎和末端分枝坏死。对捕获的成虫进行的初步筛选导致分离出具有不同生活策略的离散数量的真菌类群，范围从真正的共生菌（例如 Ambrosiella xylebori）到植物病原体（镰刀菌属）。在本研究中，应用高通量测序来确定与从三个地中海木本宿主 Quercus ilex、Laurus nobilis、和 Ceratonia silqua。调查了季节和寄主在确定相关真菌群落组成方面的影响。共有 206 个 OTU 组成了与 X.compactus 相关的真菌群落。三个宿主之间共享了 18 个 OTU，包括 A. xylebori 和 Fusarium solani complex 的成员。除了两个之外，所有其他人以前都与甲虫有关。206 个 OTU 中有 69 个被解析到物种水平，确定了 60 种不同的真菌物种，其中 22 种已在文献中报告为与甲虫或其他昆虫有关。功能协会将大部分真菌物种分配给腐生菌和植物病原体。强调了季节性和寄主对真菌群落组合的影响，表明昆虫在入侵过程中获得了新的真菌类群。