The Diptera or "true flies" constitute one of the largest orders of insects in the biosphere. They are as diverse morphologically and biologically as they are numerous, and many groups have evolved spectacular structural adaptations commensurate with their environment and biology. During their long evolutionary history, virtually every terrestrial niche has been occupied by the Diptera, making them one of the most successful groups of organisms on Earth. Many have co-evolved in association with other organisms and become highly specialized parasites or parasitoids of a range of disparate groups in the Plant and Animal Kingdoms. Whether focusing on their systematics, biology, biogeography, conservation, or the more applied aspects, the Diptera remain a fascinating and intriguing group.
The applied significance of the Diptera can not be overestimated. On the negative side, they are especially significant in Africa, as numerous species are vectors of deadly insect-borne diseases and other pathogens to man and his livestock (e.g. Culicidae, Glossinidae, Ceratopogonidae), including Malaria, Trypanosomiasis (and the animal equivalent Nagana), Leishmaniasis, and African Horse Sickness (AHS), to name but a few. Others are serious agricultural pests and can significantly affect crop yields or damage produce (e.g. Tephriidae, Cecidomyiidae, Chloropidae, some Muscidae), impacting negatively on a country's ability to export produce and consequently its GDP. On the positive side, the role of Diptera in pollination has received increasing attention in recent years, with studies indicating that the Diptera may be far more significant in pollination biology than previously considered. Many parasitoid species (especially the Tachinidae) are potential agents in biological control, while others are now used routinely in forensic investigations (Calliphoridae, Piophilidae, etc.). The Diptera are also probably the most significant group in terms of the degeneration and decomposition of animal and other organic matter, being instrumental in the breakdown and release of nutrients back into the soil.
Figures for 2009, available from the BioSystematic Database of World Diptera (Evenhuis, Pape, Pont & Thompson 2009), indicate that 152,986 species of Diptera are known worldwide, of which 19,590 are known from the Afrotropical Region, representing a mere 13% of the world fauna. According to recent predictions (Kirk-Spriggs & Stuckenberg 2009), there are upwards of 30,000 species remaining to be described from the latter region, indicating that only two-thirds to a half of the Diptera fauna of that region are currently known. If the total number of species added to the regional list from 1981–2006 is considered (3,371), this gives an average of 129 new species annually. Hypothetically, at that average rate of taxonomic growth it would take almost three centuries (231–289 years) to reach the end of the discovery phase (Kirk-Spriggs & Stuckenberg 2009).
There are currently only a handful of practicing dipterologists in Africa; most of whom are based in South Africa. If we are to meet the challenges ahead in the description of this vast array of undescribed species, it is increasingly important that the international dipterological community focuses its interest on the Afrotropical Region. A first step in this direction is the production in progress of a high-quality, professional Manual of Afrotropical Diptera, which will provide information on the Afrotropical fauna at large and identification keys specifically.
We currently have secured committed chapter contributions for all 109 systematic chapters and 11 of the 12 introductory chapters. This project is truly an international effort, with contributors from 23 countries (on six continents), namely: Australia, Belgium, Brazil, Canada, Czech Republic, Denmark, France, Germany, Hungary, Ireland, Israel, Italy, Netherlands, Norway, Poland, Russia, Singapore, South Africa, Sweden, Switzerland, Ukraine, United Kingdom, and United States of America.
The Manual is to be set and published by the Publications Unit of the South African National Biodiversity Institute (SANBI).