The four-yearly International Congress of Dipterology (ICD) is the major event for dipterists from all over the world. This year's congress, held in San José, Costa Rica, was attended by 219 delegates from 35 countries. Given the geographical location, it is not surprising that the congress was dominated by delegates from Brazil, Canada and the United States, but four delegates based in South Africa attended: J. Londt and B. Muller (Natal Museum, Pietermaritzburg), K. Williams (Durban Museum of Natural Sciences) and A.H. Kirk-Spriggs (National Museum, Bloemfontein); all made oral presentations. Four excellent plenary addresses were presented: "Maggots and mayhem" by L. Goff; "Fossils, biogeography and evolution of Diptera" by D. Amorin; "Contact courtship devices and sexual selection in Diptera" by W.G. Eberhard; and "Diversification and specialization in the Neotropics: insights from Blepharoneura" by M. Condon. Eberhard's address, illustrating clasping mechanisms in the Sepsidae and X-ray video footage of living Glossina in copula, was particularly memorable. The programme included 11 symposia: "Advances in Afrotropical Dipterology", "Forensic Diptera", "Phylogeny and taxonomy within the 'orthorrhaphous' Brachycera", "Evolution and ecology of insect-host relationships", "Advances in Neotropical dipterology: rediscovering the New World", "Empidoidea", "Getting Diptera taxonomy up-to-date: new frontiers and the web", "Evolutionary ecology of Diptera pollinators", "Morphology", "Higher level phylogeny of flies", and "Biodiversity survey projects". Seven workshops also took place, dealing with specific themes or taxonomic groups: Agricultural Diptera, Calypratae, Syrphidae, Sciaroidea, Ceratopogonidae, 'Acalypratae', and Culicomorpha. It was disheartening that there were no sessions on medical or veterinary Diptera, given the significance of flies as vectors of human and livestock diseases. Furthermore, only six presentations were included in the workshop on agricultural Diptera. However, there was a marked increase in the number of oral presentations and posters on forensic entomology, this perhaps reflecting a change in emphasis in applied fields of dipterology. Of particular interest to readers of African Invertebrates may be the symposium "Advances in Afrotropical Dipterology"; the first symposium at any ICD to focus specifically on Afrotropical Diptera. Its main objectives were to direct attention to Afrotropical Diptera before the proposed publications of a Manual of Afrotropical Diptera and to assess current knowledge of all major groups of Diptera occurring in the region. The symposium began with a dedication to the late Brian Roy Stuckenberg (1930-2009), highlighting his life, career and major achievements, and was followed by 19 talks covering all the major groups of Diptera, many of which were overviews of specific families. The keynote talk, by Peter Cranston, was "What advances have been made in the last decade in Afrotropical Dipterology?" and focused on advancement in the knowledge of the Chironomidae by the late Paul Freeman and Arthur Harrison. The presentations highlighted shortfalls in our knowledge of Afrotropical Diptera and the urgent need for an Afrotropical manual to facilitate identification and further training. The symposium ended with the official launch of the Manual of Afrotropical Diptera project, appropriately followed by an informal celebration sponsored by E. Oppenheimer & Son, South Africa. Seventy-seven posters were presented on a wide range of topics. This year saw the dominance of Brazilian students and the quality of the research presented was impressive, especially the graphics of the posters and recent advances in the quality of digital imaging of specimens, particularly male terminalia. One poster that received much attention was entitled "Shine on your crazy diamonds! - Diversity of structural wing colours in Diptera", by J. Kjærandsen. He used a stunning series of colour images to illustrate a visual identification map and potential signalling system in various groups of Diptera, formerly overlooked by biologists. From a personal perspective, the poster "Antlered flies: new species of Richardia R.-D. (Richardiidae) with antler-like genal projections" by D. Wendt and R. Ale Rocha, was noteworthy in two respects: the amazing genal structures described, and the excellent images of one of the few families of Diptera absent from the Afrotropics. In another poster, J.-C. Vala provided details of the long-awaited major monograph the Biology of snail-killing Sciomyzidae flies. An advance copy of his book (with L. Knutson) was available to view (Fig. 1). The ICD Council discussed the formation of an International Society of Dipterology and it was decided that the concept should become a reality. It was agreed that the 8th International Congress of Dipterology will take place at Kongresshotel, Potsdam, Germany in 2014. Germany has a long tradition of dipterology and an active body of 127 dipterists. The ICD8 Organizing Committee includes N. Dorchin, M. Kotrba, F. Menzel and J. Ziegler. Th. Pape was elected Chairman and A.H. Kirk-Spriggs was elected to the ICD Council. D. Barraclough did not stand for re-election. The congress programme, abstract volume and list of delegates are available as PDF files, on the ICD website: http://www.uoguelph.ca/nadsfly/ICD/ICDhome.htm.