tsetse

Tsetse refers to blood-feeding flies of the genus Glossina, in the family Glossinidae. Tsetse flies are vectors of African trypanosomiasis, a disease affecting humans and animals in sub-Saharan Africa. There are several species grouped into three subgenera, with distinct ecological preferences and host ranges.

Biology and life cycle: Tsetse flies are one of the few insects that give birth to live young (adenotrophic viviparity). After a courtship and a short gestation, a female produces a single fully developed larva, which immediately pupates in the soil. The pupal stage lasts days to weeks depending on species and climate. Adults feed on vertebrate blood, typically at intervals of several days, and live for weeks to months.

Distribution and habitat: Tsetse are native to sub-Saharan Africa and are associated with savanna, woodland, and riverine habitats that provide shade and suitable humidity. They are not uniformly distributed; populations cluster in certain ecological zones and are influenced by climate and host availability.

Role in disease and impact: Several species of Trypanosoma parasites circulate in tsetse populations. In humans, Trypanosoma brucei gambiense and T. b. rhodesiense cause human African trypanosomiasis (sleeping sickness). In animals, various trypanosomes cause animal trypanosomiasis (nagana). The disease burden limits livestock production and livelihoods in affected regions.

Control and management: Vector control uses integrated approaches, including insecticide-treated targets and traps, insecticide-treated livestock, habitat management, and, in some cases, the sterile insect technique. Vaccines are not available for trypanosomes in humans. Sustainable control requires surveillance, community involvement, and coordination across borders.