Tsetse fly

Tsetse (/ˈsiːtsi/, US /ˈtsiːtsi/, or UK /ˈtsɛtsi/), sometimes spelled tzetze and also known as tik-tik flies, are large biting flies that inhabit much of midcontinental Africa between the Sahara and the Kalahari Deserts. They live by feeding on the blood of vertebrate animals and are the primary African biological vectors of trypanosomes, which cause human sleeping sickness and animal trypanosomiasis, also known as nagana. Tsetse flies include all the species in the genus Glossina, which are generally placed in their own family, Glossinidae.

Tsetse have been extensively studied because of their disease transmission. These flies are multivoltine, typically producing about four generations yearly, and up to 31 generations total over their entire lifespans.

Tsetse are crudely similar to other large flies, such as the housefly, but can be distinguished by various characteristics of their anatomy, two of which are easy to observe. Tsetse fold their wings completely when they are resting so that one wing rests directly on top of the other over their abdomens. Tsetse also have a long proboscis, which extends directly forward and is attached by a distinct bulb to the bottom of their heads.