tsetse fly, name for any of several bloodsucking African flies of the genus Glossina, and in the same family as the housefly. The larva of the tsetse fly develops inside the body of the mother until it is ready to pupate in the soil. A number of the 21 species can transmit to humans the trypanosomes that cause the Gambian and Rhodesian forms of African sleeping sickness (see trypanosomiasis; encephalitis). The tsetse fly also carries the trypanosomes that cause nagana and other diseases of wild and domestic animals. Clearing the brush that the flies inhabit helps to get rid of them; DDT has also been used to exterminate them. Tsetse flies are classified in the phylum Arthropoda, class Insecta, order Diptera, family Muscidae. See insect.

Any of about 21 species (genus Glossina, family Muscidae) of African bloodsucking dipterans that are robust, sparsely bristled, and usually larger than a housefly. They have stiff, piercing mouthparts. Only two species commonly transmit the protozoan parasites (trypanosomes) that cause human sleeping sickness: G. palpalis, found primarily in dense streamside vegetation, and G. morsitans, found in more open woodlands. The female requires a sufficient blood meal to produce viable larvae, but both sexes suck blood almost daily.

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