The distribution of the vectors of African pathogenic trypanosomes.

The author lists the species, subspecies and races of tsetse fly now recognized in three morphologically distinct groups. The distribution of each group is mapped and described in relation to climate and vegetation, with some indication of the part played by past climates and orogenies in determining the modern pattern. The importance of different species as vectors of human or bovine trypanosomiasis, or both, is noted, and examples are given of the part played by human settlement as a secondary limiting factor. The author suggests that many modern problems of control are the consequences of the recent invasion of the African ecosystem by the outside world. Although there are local exceptions, the broad pattern of Glossina distribution has not been significantly changed by the entomological approach to the trypanosomiasis problem.