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RouBAUD (E.). Les Mouches Tsetses en Afrique Occidentale Franpaise. 

 Nos Connaissances actuelles sur leur Histoire et leur Role patho- 

 gene. — Bull. Comite Etudes Hist. & Scientif. Afr. Occ. Frangaise, 

 Paris, no. 4, July-September 1920, pp. 257-300, 1 map, 7 figs. 

 [Received 25th March 1922.] 



The chief feature of this paper is a map showing the distribution of 

 tsetse-flies and of the various forms of trypanosomiasis in French 

 West Africa. This is the result of a survey and study undertaken 

 during the years 1906-16 by MM. Bouet and Roubaud, during 

 which some two-thirds of West Africa were traversed, while the works 

 of other investigators have also been studied in the course of its pre- 

 paration. It must be remembered that the whole system of economic 

 life in that country is dependent upon the raising of cattle, and this is 

 much affected by the presence of Glossina, a genus differing from any 

 other biting fly in that it lives entirely upon blood and has no need 

 of water, which it is said never to touch in nature. Cold-blooded 

 animals, such as crocodiles, are only attacked in the absence of other 

 food [see, however, R.A.E., B, viii, 132]. The author states that, 

 like Kleine, he has observed that flies that feed exclusively on crocodiles 

 soon lose their fertility. For the reproductive functions to be normal, 

 the females must feed on the blood of mammals or birds. As big 

 game is considered to be the food preferred at all times by Glossina, 

 the great game zones, where the human population is small, are 

 indicated on the map, being important as reservoirs both of the fly 

 and of the virus of trypanosomiasis. 



A key is given to the species of Glossina occurring in French West 

 Africa, viz. G. tachinoides, Westw., G. palpalis, R.-D., G. morsitans, 

 Westw., G. longipalpis, Wied., G. fusca, Wlk., G. nigrofusca, Newst., 

 G. tabaniformis, Westw., G. medicorum, Aust., and G. pallicera, Big. 

 Of these, the first four are by far the most important and the most 

 widespread, G. morsitans being essentially the big-game fly. The 

 habitat and biology of these species are discussed. Seasonal migration 

 of the flies and the influence of meteorological conditions on their 

 extension are explained, as well as their relation to geographical 

 and geological conditions. Their distribution is not absolutely based 

 on conditions of vegetation or climate, and while G. pallicera and 

 G. fusca are almost entirely limited to forest conditions, G. tachinoides 

 and G. longipalpis may also be found in forest zones, though this is 

 not their usual habitat, and G. morsitans, which is essentially a species 

 of the plains, where the big game is found, may also occur in wood- 

 lands covered with thick brushwood, at short distances from water. 

 G. tachinoides and G. longipalpis are essentiafly bush species, feeding 

 on wild animals, but G. palpalis may frequently be found in close 

 proximity to villages. The larger the number of flies, however, the 

 less will be the danger to man, as numbers indicate a plentiful food 

 supply, and cattle in this respect are certainly a protection to the 

 inhabitants of such villages. 



In the face of different climatic conditions, certain physiological 

 reactions are found to occur among the species of Glossina, which are 

 of great importance in that they influence their capacity for trans- 

 mission of the various forms of trypanosomiasis. Investigation over 

 a number of years has proved that the same species of Glossina is not 

 capable of transmitting a given virus in every locality where it occurs. 

 There are at least six forms of trypanosomiasis in French West Africa, 

 four of which are specifically tsetse-borne, namely, sleeping sickness, 



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