Seasonal Survey of horse flies by Dr Kirsten Williams

Horse flies are usually seen as a nuisance that bite, but they are also important vectors of disease. While most people are aware that Tsetse flies are responsible for spreading sleeping sickness, researchers have found that some species of horse fly are also able to transmit sleeping sickness and several other diseases. 

A project has been initiated by staff at the museum to investigate the seasonal distribution of horse flies in a coastal forest versus an Afromontane forest and the surrounding grasslands over a three-year period. This project will look at the seasonal variations of species over three years and will screen horse flies to determine what pathogens they may be carrying. It will also compare the two types of forest to determine if there is a difference in the species composition. Two field trips a year are planned to collect horse flies over the three-year period – one in early summer and one in later summer.  Four different trap types will be used to catch the horse flies – Manitoba, Ngu, horizontal and malaise traps – to determine which trap type is most efficient at catching these flies.

The results of this project will increase our knowledge about what diseases horse flies carry and are potentially spreading. This will assist in management plans to protect livestock. This project is funded by the National Research Foundation of South Africa with the principle investigators being Dr Kirstin Williams from the KZN Museum and Dr Loki Snyman from the University of Saskatchewan, Canada. 

Photo credit: Mandisa Ndlovu