How many species of tsetse are there?

There are 29 species and subspecies of tsetse, divided into three groups with contrasting ecological and behavioural characteristics.

First, the Morsitans group of tsetse is found mainly in savannah woodlands across sub-Saharan Africa. These species are highly mobile and use a combination of visual and olfactory stimuli to locate their hosts. The group includes the more important vectors of animal trypanosomiasis such as G. pallidipes, G. morsitans subspp., G. longipennis and G. austeni.

Second, the Palpalis group comprises species found mainly in riverine woodland of west and central Africa. Species from this group are generally less mobile, being confined to their riverine habitats, and use visual cues, rather than olfactory ones, to locate their hosts. The group includes important vectors of human sleeping sickness such as G. fuscipes and G. palpalis subspp.

Third, the Fusca group comprises species typically found in humid forests. Species from this group are generally considered to be less important as a vector, largely because their natural habitat is less used by livestock and people. Nonetheless, some species (eg, G. brevipalpis) have been implicated as significant vectors of animal trypanosomiasis.