Data from: A comprehensive DNA barcode database for Central European beetles with a focus on Germany: adding more than 3,500 identified species to BOLD

Beetles are the most diverse group of animals, and are crucial for ecosystem functioning. In many countries, they are heavily used for environmental impact assessment, but even in the well-studied Central European fauna, species identification can be very difficult. A comprehensive and taxonomically well curated DNA barcode library could remedy this deficit and also could link hundreds of years of traditional knowledge with next generation sequencing technology. However, such a beetle library is missing to date. This study provides the globally largest DNA barcode reference library for Coleoptera for 15,948 individuals belonging to 3,514 well-identified species (53% of the German fauna) with representatives from 97 of 103 families (94%). This study is the first comprehensive regional test of the efficiency of DNA barcoding for beetles with a focus on Germany. Sequences >500bp were recovered from 63% of the specimens analyzed (15,948 of 25,294) with short sequences from another 997 specimens. Whereas mostspecimens (92.2%) could be unambiguously assigned to a single known species by sequence diversity at CO1, 1089 specimens (6.8%) were assigned to more than one Barcode Index Number (BIN), creating 395 BINs which need further study to ascertain if they represent cryptic species, mitochondrial introgression, or simply regional variation in widespread species. We found 409 specimens (2.6%) that shared a BIN assignment with another species, most involving a pair of closely allied species as 43 BINs were involved. Most of these taxa were separated by barcodes although sequence divergences were low. Only 155 specimens (0.97%) show identical or overlapping clusters.

甲虫是物种多样性最高的动物类群，对生态系统功能发挥至关重要。在诸多国家，甲虫被广泛应用于环境影响评价工作，但即便在研究较为深入的中欧动物区系中，物种鉴定仍极具挑战性。一套全面且经分类学严谨校核的DNA条形码（DNA barcode）参考库，不仅可弥补这一短板，还能将数百年积累的传统分类学知识与下一代测序技术相结合。然而截至目前，全球仍未建成此类甲虫专属的DNA条形码参考库。本研究构建了目前全球规模最大的鞘翅目（Coleoptera）DNA条形码参考库，涵盖15948号标本，隶属于3514个已准确鉴定的物种（占德国已知鞘翅目区系的53%），标本覆盖103个科中的97个（占比94%）。本研究是首个以德国为研究区域、全面评估DNA条形码技术对甲虫鉴定效能的区域性试验。本次分析共纳入25294号标本，其中63%的标本（15948号）成功获取了长度大于500bp的有效序列，另有997号标本仅获得了短片段序列。基于细胞色素氧化酶亚基I（CO1）的序列多样性，92.2%的标本可被明确归为单一已知物种；6.8%的标本（1089号）被划归至多个条形码索引号（Barcode Index Number，BIN），共形成395个待进一步研究的条形码索引号，需明确其究竟代表隐存种（cryptic species）、线粒体渐渗（mitochondrial introgression），还是广布物种的区域种群差异。研究发现2.6%的标本（409号）与其他物种共享同一条形码索引号，其中多数涉及一对近缘物种，共涉及43个条形码索引号。尽管这些类群间的序列分歧度较低，但大部分仍可通过DNA条形码进行区分。仅有0.97%的标本（155号）的聚类结果完全一致或存在重叠。