Review of tsetse flies and trypanosomosis in South Africa.

The history of tsetse flies and nagana (trypanosomosis) in South Africa, and especially in Zululand, is reviewed. Four valid tsetse fly species have been recorded from South Africa. Glossina morsitans morsitans disappeared from the most northerly parts of South Africa during the rinderpest epizootic between 1896-1897. Of the three remaining species that occurred in Zululand, now part of KwaZuluNatal Province, G. pallidipes was the most common vector of nagana in cattle, but was eradicated from this area in 1954. G. brevipalpis and G. austeni remained but were responsible for only a few sporadic cases of nagana up until 1990. A widespread outbreak occurred in 1990 where cattle served by 61 diptanks were found infected with Trypanosoma congolense and T. vivax. Dipping of cattle in a pyrethroid plus the therapeutic treatment of infected animals brought the disease under control. The outbreak also led to a trial to control G. brevipalpis from the most northerly parts of the Hluhluwe/Umfolozi Game Reserve making use of target technology as for savannah species. The results were not satisfactory and the trial was discontinued until further research could provide a more appropriate system for the control of this species. A Tsetse Research Station was established at Hellsgate near St. Lucia Lake where research on G. brevipalpis and G. austeni is conducted into ways and means of monitoring and controlling these species.