The fly family Tabanidae (horse flies) includes an estimated 4000 extant species distributed throughout the world. Nearly all are blood-feeders as adults, but many are also important pollinators of flowers. The biology and taxonomy of horse flies has an important historical legacy, but modern revisionary work has lagged behind other dipteran groups due to a generational reduction in the number of horse fly taxonomists and to a perceived ""difficult"" morphology, which is often similar for many standard fly characters. Current classifications are heavily biased by previous work on better known fly groups, while many smaller groups need to be addressed to provide context and new characters from which more comprehensive phylogenetic revision can proceed. This study will integrate modern tools and practices in taxonomy and systematics to address the need for increased attention to horse fly biodiversity and classification. The research team extends a successful collaborative framework with expertise in monographic, phylogenetic, and bioinformatic data generation, and builds on active efforts initiated by previous Partnership for Enhancing Expertise in Taxonomy (PEET) projects.

This project will foster collaboration in laboratory and field studies between faculty and students from Australia and the US. The results of the work will be made available to scientists and the general public via a database and web site directly associated with the project, as well as the integration of taxonomic tools and a project database. Projects are designed to encourage both mentorship and collaboration amongst the student trainees. In addition to their taxonomic work, each trainee will be asked to specialize in one of three general areas: bioinformatics techniques, computational/analytical techniques, or outreach methods. As they develop in these areas, they will be expected to mentor each other in their chosen expertise and to produce products that are disseminated through the projects web portals. The project involves a strong component of academic training for postdoctoral associates, graduate, and undergraduate students. In addition, there is a comprehensive program of outreach, including educational material that will be presented via the project web site and several other online resources for undergraduate and K-12 levels produced by the collaborating universities and through the Education and Outreach resources of the National Evolutionary Synthesis Center.

Project Report

The horse flies (Tabanidae) include over 4,000 species and are well known as pests of humans and livestock due the blood feeding habits of adult females. Male and female flies also visit flowers for pollen and nectar, and some groups are specifically adapted as pollinators. The species diversity and uniform anatomy of adult horse flies makes them a difficult group to identify, study, and classify. Detailed study of the morphology, genetics, and biology of horse flies can provide a new evolutionary basis to understand the diversity of the group and to test hypotheses about the adaptations that influence their ecological roles and behavior. These studies place the discovery, description, and informatics of horse fly species, along with their behavior and anatomy into a predictive classification for further research. This project involved a team of researchers assembled to investigate the horse flies with molecular and anatomical data to improve their classification and to investigate the history of their speciation and behavioral change. These studies are accomplished through a program of interdisciplinary training integrating bioinformatic, genetic, taxonomic and biocollections research. This resulted in a series of studies that were conducted and are published. Project-based fieldwork led to discovery of multiple new species of horse flies that are both blood feeders and pollinators in South Africa, Chile, Australia, and Ecuador. Analysis based on anatomical features has brought many new species previously unknown to science, to light. Analysis of genetic data from a broad sample of horse fly species reveals a new pattern of relationships among the major lineages and reveals that the group originated, 120 million years ago, well after the origin of mammals, but underwent major diversification in the Paleogene, 60-30 mya, at a time when mammals were also experiencing major evolutionary radiations. Our results also show that scionine Tabanidae were well established in the southern hemisphere supercontinent, Gondwanaland, and had diversified into major lineages before the separation of the southern continents. Professional and scientific training was provided to a postdoctoral researcher, graduate, and undergraduate students, as well as collaborators from Australia and Brazil. The results improve understanding of these insects that were otherwise poorly known, and the revised classifications are being used to understand evolutionary processes associated with pollination, geographic distributions, and molecular evolution. In addition to disseminating the results of this project to other researchers through traditional publications and conference proceedings, members of the project team delivered numerous presentations in the United States and abroad to local people, teachers, and students.

National Science Foundation (NSF)
Division of Environmental Biology (DEB)
Application #
Program Officer
Simon Malcomber
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
North Carolina State University Raleigh
United States
Zip Code