The vector that transmits trypanosomiasis is the tsetse fly. Trypanosomiasis, also known as African sleeping sickness, is a disease caused by the parasite Trypanosoma brucei, which is transmitted to humans and animals by the tsetse fly. The tsetse fly is found in sub-Saharan Africa and feeds on the blood of mammals, including humans. When the fly bites an infected mammal, it picks up the parasite, which can then be transmitted to the next mammal it bites, including humans. Therefore, the tsetse fly plays a significant role in the transmission and spread of trypanosomiasis.