Data from: Host range expansion of native insects to exotic trees increases with area of introduction and presence of congeneric native trees

1. Exotic tree species are widely used in forest plantations for their often high productivity and performance compared to native trees. However, these advantages may be compromised by herbivore damage. 2. A list of European insect species that have expanded their host range to one of 28 exotic tree species introduced to Europe was compiled from a systematic literature review. The number of successful expansions was analysed using three predictors: (1) phylogenetic relatedness between exotic and European tree species; (2) area covered by exotic tree species in Europe; and (3) time since their introduction into Europe. 3. In total, 590 host expansions of native insects to exotic trees were found, mainly of polyphagous species (43%); 25% of the cases reported some type of damage. Bark and wood borers, and defoliators were the dominant guilds. 4. The number of recruited native insect species and cases where major damage occurred were positively correlated with the geographical extent of exotic trees in Europe and the presence of congeneric native trees. 5. Synthesis and applications. The use of exotic tree species creates opportunities for native insect herbivores to expand their host range and increase their damage if they are widely planted next to native congeners. Risk assessment studies are recommended when introducing new tree species for forestry plantations. Risk assessments should include trials on susceptibility to any potential damaging organisms in the introduced range.1. 外来树种（exotic tree species）因相较乡土树种（native trees）通常具有更高的生产力与表现性，被广泛应用于人工林营建中。然而，这些优势可能因植食性昆虫危害（herbivore damage）而受损。 2. 本研究通过系统综述（systematic literature review）整理了一份欧洲昆虫物种名录，这些昆虫已将寄主范围（host range）拓展至28种引入欧洲的外来树种之一。本研究采用三类预测因子对成功拓展寄主范围的昆虫数量进行分析：（1）外来树种与欧洲乡土树种间的系统发育亲缘关系（phylogenetic relatedness）；（2）外来树种在欧洲的分布面积；（3）外来树种引入欧洲的时间跨度。 3. 总计发现590起乡土昆虫向外来树种拓展寄主范围的事件，其中多食性物种（polyphagous species）占比43%，为主要类群；25%的事件报告了不同程度的危害。蛀干与蛀木害虫（bark and wood borers）及食叶害虫（defoliators）为占主导的功能群（guilds）。 4. 新增乡土昆虫物种数量以及发生严重危害的事件数，均与外来树种在欧洲的地理分布范围以及同属乡土树种的存在呈正相关。 5. 结论与应用（Synthesis and applications）：若外来树种与同属乡土树种连片广泛种植，其应用将为本土植食性昆虫拓展寄主范围、加重危害提供契机。因此，在为林业人工林引入新树种时，建议开展风险评估（risk assessment）研究。此类风险评估应包含对引入区域内潜在有害生物的敏感性（susceptibility）测试。