This animation shows the lifecycle of typical African Trypanosomes as they are transmitted from cow to tsetse fly to cow. The lifecycle is mostly the same for Trypanosoma brucei (including T. b. gambiense and T. b. rhodesiense), Trypanosoma vivax and Trypanosoma congolense. The animation shows the lifecycle of T. brucei subspecies ; T. congolense is similar excpet that after it has developed in the midgut it goes forward to the proboscis not the salivary glands and T. vivax does not have a midgut stage at all but develops in the proboscis. T. vivax has become wide spread in South America presumably because its simpler lifecycle in the tsetse fly has made it easier for it to adapt to different vectors in South America. The importance of mechanical transmission in Africa by flies other than tsetse flies is not known.