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.
