Beetles are commonly moved among continents with international trade. Baited traps set up in and around entry points are commonly used to increase chances of early-detection of incoming species and complement visual inspections. A still underestimated benefit of this surveillance approach is the high number and diversity of collected bycatch species. In this study, we exploited a multiyear surveillance program carried out with baited traps at five Spanish ports and their surrounding natural areas to investigate i) the importance of identifying bycatch to more promptly detect nonnative species belonging to non-target groups; ii) patterns of native and nonnative species richness and abundance inside the port areas vs. surrounding natural areas; iii) the occurrence of spillover events between natural areas surrounding ports and the port areas, and iv) whether the native species most commonly introduced into other countries are more abundant in port areas than in surrounding natural areas. A total of 23,538 individuals from 206 species representing 33 families were collected. The number and taxonomic diversity of the 26 bycatch nonnative beetle species testified that the identification of these unintentionally trapped species can provide additional information on ongoing invasions. Patterns of spillover and native species richness and abundance in port areas vs. surrounding natural areas highlighted a differential ability of different beetle families to colonize port areas. Finally, native species most commonly introduced into other countries were more abundant in port areas than in their surroundings, while the opposite trend occurred for native species that have not been introduced elsewhere. Our study highlighted that the use of traps baited with generic attractants can aid in early-detection of nonnative beetle species, and that the identification of native species can provide useful information on the risk of introduction in other countries.

中文翻译：

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调查入境点及其周围的甲虫群落可以改善国家和国际范围内的监测

 甲虫通常通过国际贸易在各大洲之间移动。在入口点及其周围设置诱饵陷阱通常用于增加早期发现传入物种的机会并补充目视检查。这种监测方法的一个仍然被低估的好处是所收集的兼捕物种的数量和多样性。在这项研究中，我们利用在西班牙五个港口及其周边自然区域使用诱饵陷阱进行的多年监测计划来调查 i) 识别兼捕渔获物以更迅速地检测属于非目标群体的非本地物种的重要性；ii) 港口区内本地和外来物种丰富度和数量与周围自然区域相比的模式；iii) 港口周围自然区域与港区之间发生溢出事件，iv) 最常引入其他国家的本地物种在港口地区是否比周围的自然地区更丰富。总共收集了来自 33 个科 206 个物种的 23,538 个体。26 种兼捕的非本地甲虫物种的数量和分类多样性证明，识别这些无意捕获的物种可以提供有关持续入侵的更多信息。港口地区与周围自然地区相比的溢出模式和本地物种丰富度和丰度凸显了不同甲虫科在港口地区定居的能力差异。最后，最常引入其他国家的本地物种在港口地区比其周围地区更丰富，而尚未引入其他地方的本地物种则出现相反的趋势。我们的研究强调，使用带有通用引诱剂的诱捕器可以帮助早期发现非本地甲虫物种，并且本地物种的识别可以提供有关引入其他国家的风险的有用信息。