Doctoral Dissertation Research: Phylogeny, Classification and Biodiversity of Robber Flies (Diptera: Asilidae) with Special Reference to Leptogastrinae

生物多样性的研究具有巨大的科学和社会价值，特别是在生物多样性受到严重威胁的今天。本论文项目涉及一组昆虫的调查，全世界约有7000种已描述的物种，是种类最丰富的真蝇科之一。盗蝇是一种易识别的昆虫，在昆虫捕食者中起着重要的作用。尽管许多科学出版物涉及这些苍蝇，但物种的进化关系仍然模糊不清。这项研究的重点是钩胃亚科的物种，目前已知的462种。这一群体的独特之处在于其独特的形态特征，其狭窄的身体很可能是对草类生活的适应。许多其他种类的罗伯蝇也栖息在草原和草原上，但缺乏这样一套独特的相似形态特征。本项目通过(1)对盗蝇物种的进化关系提出了充分证实的假设，(2)为盗蝇亚科物种提供了物种描述和鉴定关键，(3)在生物多样性热点sensuconservation International上分析了盗蝇物种的分布和物种丰富度。这些发现将允许讨论所有强盗蝇的栖息地偏好的特征进化，强调草栖物种，并使用成年苍蝇的形态特征和DNA序列将它们与细腹蝇的物种进行比较。实地调查是在东南亚进行的，以收集强盗蝇的种类进行分析，因为该地区拥有最不为人所知和采样的动物群。两个主要的自然历史博物馆收藏的标本来自东南亚-伦敦，英国和阿姆斯特丹，荷兰-检查历史标本突出的重要性，以确定新收集的材料。在生物多样性危机研究的众多目标群体中，昆虫的代表性一直不足。本论文项目将物种最丰富的蝇类之一纳入生物多样性分析。向世界各地传播科学知识是极其重要的。在本项目中收集的物种描述和识别密钥正以所需的印刷格式在科学期刊和万维网上作为综合生物多样性数据库发表，从而使包括昆虫学家和保护生物学家在内的全世界读者可以获得这些知识。在美国国家科学基金会资助的本科生研究经验计划下，本科生在暑期实习期间接受修订分类法的培训，以教育未来的科学家识别，描述和说明物种并发表结果的方法。由美国国家科学基金会（nsf）资助的广泛研究项目“组装生命之树——真蝇”将直接受益于拟开展的对Asilidae进化关系的研究。

The study of biological diversity has immense scientific and social value, especially today as biodiversity is under serious threat. This dissertation project deals with the investigation of a group of insects that, with approximately 7,000 described species world-wide, is one of the most species-rich families of true flies. Robber flies (Asilidae) are easily recognized and play an important role as insect predators. Although many scientific publications deal with these flies, evolutionary relationships of the species remain obscure. This study focuses on species of the subfamily Leptogastrinae, currently known from 462 species. This group is distinct due to peculiar morphological characteristics associated with a narrow body that are most probably adaptations to a life among grasses. Many other robber-fly species inhabit prairies and grasslands as well, but lack such a distinctive suite of similar morphological features. This project enhances the knowledge about robber flies by (1) presenting well-corroborated hypotheses of the evolutionary relationships of species of robber flies, (2) providing species descriptions and identification keys for species of the subfamily Leptogastrinae, and (3) analyzing the distribution and species richness of species of Leptogastrinae with respect to biodiversity hotspots sensu Conservation International. The findings will allow a discussion of character evolution with respect to habitat preferences of all robber flies, emphasizing grass-inhabiting species and comparing them to species of Leptogastrinae using both morphological characters of the adult flies and DNA sequences. Fieldwork is conducted in South east Asia in order to collect species of robber flies for the analyses, as this region hosts the least-known and sampled fauna. Two major natural history museums housing specimens of Asilidae from South east Asia - London, UK, and Amsterdam, The Netherlands - are visited to examine historical specimens of outstanding importance for identification of freshly collected material.Among many target groups used for studies addressing the biodiversity crisis, insects are always under represented. This dissertation project incorporates one of the most species-rich fly groups into analyses of biological diversity. The dissemination of scientific knowledge to all parts of the world is of immense importance. The species descriptions and identification keys assembled in this project are being published in required printed format in scientific journals as well as on the world wide web as integrative biodiversity databases, therefore making this knowledge available for world-wide audiences including entomologists and conservation biologists. An undergraduate student is trained in revisionary taxonomy during a summer internship under the NSF-funded Research Experience for Undergraduates program in order to educate a future scientist in methods of identifying, describing, and illustrating species and publishing the results. The extensive NSF-funded research project Assembling the Tree of Life - True Flies will directly benefit from the proposed study of the evolutionary relationships of Asilidae.