ENTOMOLOGY 279 



densely vegetated Ashanti and the Colony itself provide a suitable 

 environment for G. longipalpis, which renders the keeping of cattle 

 out of the question, except for the dwarf breeds which are resistant 

 to trypanosomiasis. Research here has been carried out by the 

 veterinary department at Pong-Tamale, under Mr. J. Stewart, 

 who has produced a report on the work (1937). Studies of tsetse 

 have been made, and it has been established, as in Nigeria, that 

 the fly occurs along the rivers except during the rainy seasons 

 when it migrates into the dry country. An intensive study has 

 been made also of the trees and other vegetation of the savannah, 

 known locally as orchard bush, and as a result, a system of clearing 

 has been worked out on the area of country grazed by the herds of 

 cattle kept at Pong-Tamale: belts of land half a mile wide are 

 cleared along the water-courses, and the brushwood is burned 

 over the stumps of those trees which are most capable of rapid 

 regeneration. It is claimed that this clearing along streams can 

 be carried out at a very low cost. Nearly the whole area of the 

 Pong-Tamale farm has been rendered free from fly, and losses from 

 trypanosomiasis among the herds have been reduced to a very 

 low level (Plate iv, p. 296.) 



In those colonies comprising French West Africa, where sleeping 

 sickness is prevalent, intensive treatment campaigns have been 

 carried out, as described in Chapter XVI. The distribution of fly 

 has been ascertained in many areas by special missions sent out 

 for the purpose, notably those of Mm. Bonet, Roubard, and Jamot 

 during 1906-16 and 1932-5. A map [Afrique Occidentale frangais 

 1935) has been published, showing the available data for all the 

 West African territories from Nigeria to Senegal. 



If it is legitimate to generalize on a subject so complex, it appears 

 that in West Africa there has been some hesitation in embarking 

 on the expenditure involved in bush-clearing and similar anti-fly 

 methods, while research work has been concentrated on the develop- 

 ment of medical treatment of sleeping sickness. It seems probable, 

 however, that large-scale anti-fly work such as that of Tanganyika 

 will eventually become essential, and will call for the organization 

 of special departments. It is sometimes suggested that the methods 

 of control discovered in Tanganyika can be applied in other terri- 

 tories without any special organization. This, however, is only 



