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

生物多样性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，大约有7,000种描述的世界各地，是最物种丰富的家庭真蝇之一。盗跖蝇（Asilidae）是一种很容易识别的昆虫，在昆虫捕食者中扮演着重要的角色。虽然许多科学出版物都涉及这些苍蝇，但该物种的进化关系仍然模糊不清。本研究的重点是Leptogastrinae亚科的物种，目前已知的462种。这一组是独特的，由于与狭窄的身体，最有可能是适应生活在草之间的特殊形态特征。许多其他的盗蝇物种也栖息在大草原和草地上，但缺乏这种独特的一套相似的形态特征。该项目通过以下方式增强了对盗蝇的认识：（1）提出了关于盗蝇物种进化关系的充分证实的假设，（2）提供了Leptogastrinae亚科物种的物种描述和识别检索表，（3）分析了Leptogastrinae物种在国际保护组织意义上的生物多样性热点的分布和物种丰富度。研究结果将允许讨论的字符进化的栖息地偏好的所有强盗苍蝇，强调草栖息的物种，并将它们与Leptogastrinae的物种使用的形态特征的成年苍蝇和DNA序列。在东南亚进行实地调查，以收集用于分析的抢劫蝇物种，因为该地区拥有最不知名和采样的动物群。两个主要的自然历史博物馆收藏了来自东南亚的Asilidae标本-伦敦，英国和阿姆斯特丹，荷兰-参观了历史标本的突出重要性，以确定新收集的材料。在许多目标群体用于解决生物多样性危机的研究，昆虫总是代表不足。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。在这个项目中收集的物种描述和识别关键字正在以所需的印刷格式在科学期刊上发表，以及在万维网上作为综合生物多样性数据库，从而使这些知识可供世界各地的观众，包括昆虫学家和保护生物学家。一名本科生在NSF资助的本科生研究经验项目的暑期实习期间接受修订分类学的培训，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。NSF资助的广泛研究项目“组装生命之树-真正的苍蝇”将直接受益于拟议的对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.