Systematic revision of the army ant-symbiont beetle genus Vatesus Sharp, 1876 (Staphylinidae: Tachyporinae: Vatesini) based on a multidisciplinary approach

行军蚁是热带生态系统中的顶级节肢动物捕食者。除了它们作为捕食者的关键作用外，从蚁鸟到节肢动物共生体的各种动物群都依赖于行军蚁的存在。例如，有几百种蚂蚁是专为入侵蚁群而生的伯奇蚁（Echitonburchellii）的近亲。军蚁客人的区系多样性在物种鉴定方面存在重大缺陷，主要是因为共生体群体的分类学几十年来一直未被触及。在这些群体中值得注意的是最丰富和最有魅力的分类群之一：Vatesus Sharp，1876。该属共有26种。自20世纪50年代和60年代的最新修订以来，它们的分类法一直保持不变。根据现代标准，历史上的Vatesus物种描述缺乏足够的细节来捕捉表型变异，因此Vatesus的物种鉴定是有问题的。至关重要的是，生殖器的描述，提供了甲虫分类的基本特征，是失踪的，但两个物种。因此，这种不可靠的分类法严重阻碍了对这些甲虫的任何研究。在过去的几年里，我收集了大量的Vatesus甲虫，包括1,600多个标本和至少10个不同的物种。此外，许多博物馆还积累了大量的标本。总的来说，这些收集工作总结了数千个标本，覆盖了广泛的地理区域。基于这些卓越的收藏和博物馆的支持，我的目标是实现对Vatesus的现代系统修订。修订将基于多学科的方法，结合形态特征和遗传位点（COI，wg，CAD）的分析。基因数据的聚类将揭示可能的候选物种。每个候选物种的代表和所有的全型将使用同步加速器产生的X射线显微断层扫描（SRµCT）进行扫描，从而对甲虫的外部和内部形态进行定性和定量分析。重要的是，使用SRµCT I将分析男性和女性生殖器，而不需要解剖标本，即类型材料保持完整。分子和形态学数据将进行协同分析，目标是稳健地揭示物种边界并根据解剖学定义它们。这种综合方法将提供严格的分析Vatesus甲虫的表型和遗传变异，这将导致详细的物种描述，符合最高的现代标准。最后，我将创建一个易于使用的二分法物种键Vatesus甲虫通过提供可视化插图举例说明通过图纸，高品质的焦点堆叠的2-D图像和3-D模型呈现的字符的差异。一个可靠的分类学和一个容易使用的物种检索表将为未来对这些神秘的社会昆虫共生体的任何研究提供基础。

Army ants are the top arthropod predators in tropical ecosystems. Besides their pivotal role as predators, a diverse fauna of animals, ranging from ant birds to arthropod symbionts, depends on the presence of army ants. For instance, several hundred species are obligate associates of the swarm-raiding army ant Eciton burchellii. The faunistic diversity of army ant guests entails major deficiencies in species identifications, mainly because the taxonomy of symbiont groups has remained untouched for decades. Notable among these groups are one of the most abundant and charismatic taxa: rove beetles of the genus Vatesus Sharp, 1876. The genus consists of 26 species. Their taxonomy has remained untouched since the latest revisions in the 1950s and 1960s. By modern standards, historical Vatesus species descriptions lack sufficient detail to capture phenotypic variation so that species identifications of Vatesus are problematic. Crucially, genitalia descriptions, which provide essential characters for beetle taxonomy, are missing for all but two species. The shaky taxonomy thus creates a serious impediment to any kind of research on these beetles. In the last years, I have compiled an extraordinary collection of Vatesus beetles, consisting of more than 1,600 specimens and at least 10 distinct species. Additionally, numerous museums have additionally accrued a huge number of specimens. Collectively, these collection efforts sum up to several thousand specimens covering a broad geographic area. Based on these remarkable collections and support of museums, it is my goal to achieve a modern systematic revision of Vatesus. The revision will be based on a multidisciplinary approach by combining the analyses of morphological characters and genetic loci (COI, wg, CAD). Clustering of genetic data will unveil possible candidate species. Representatives of each candidate species and all holotypes will then be scanned using synchrotron-generated X-ray microtomography (SRµCT), allowing for qualitative and quantitative analyses of beetles’ external and internal morphology. Importantly, using SRµCT I will analyze male and female genitalia without the need of specimen dissections, i.e. type material stays intact. Molecular and morphological data will be analyzed synergistically with the goal of robustly uncovering species boundaries and defining them based on anatomy. This integrative approach will provide a rigorous analysis of phenotypic and genetic variation of Vatesus beetles, which will result in detailed species descriptions that match the highest modern standards. Finally, I will create an easily usable dichotomous species key of Vatesus beetles by providing visual illustrations exemplifying the differences of presented characters via drawings, high-quality focus-stacked 2-D images, and 3-D models. A solid taxonomy and an easily usable species key will provide the foundation for any kind of future research on these enigmatic social insect symbionts.