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NOTES ON THE BLOOD-SUCKING INSECTS OF EASTERN 



TROPICAL AFRICA. 



By S. A. Neave, M.A., B.Sc. Oxon. 



(Plates X. and XI.) 



Owing to the very limited time available during my stay in England, it has 

 not seemed advisable to attempt any general account of so extensive a region as 

 that covered by my recent journey through Tropical East Africa. This region 

 extends practically from the Zambesi River to the Upper Nile, and is included 

 in 12 degrees of longitude and no less than 22 parallels of latitude. It comprises 

 all types of country from open plains to dense forests, and elevations from sea- 

 level to 10,000 feet. This area includes, in addition to a large portion of the 

 Eastern Tropical subregion, a small portion of the South African subregion and. 

 in Uganda, of the Western Tropical subregion. The entomological study of so 

 large an area involves a great variety of interesting questions and an even more 

 bewildering diversity of insect life. The economic relations of these numerous 

 species with man and his domestic animals present a large number of problems, 

 in regard to many of which much additional evidence is required. 



One of the most urgent of these problems at the present time in Eastern Africa, 

 or indeed in any part of the continent, viz. : the occurrence of human trypano- 

 somiasis in Nyasaland and Northern Rhodesia, outside the distribution of 

 Glossina palpalis — is already being studied by two Commissions on the spot. 



Apart from this important question, all the countries under discussion have to 

 contend with other diseases borne by blood-sucking organisms, and it is clear 

 that all the local Governments, especially in Nyasaland and on the coast belt of 

 British East Africa, will find it imperative during the next few years to spend 

 large sums in combating these serious hindrances to human progress in Tropical 

 Africa. 



From the entomological standpoint it is of the utmost importance that too fine 

 a line should not be drawn between the insects which, in the present very limited 

 state of our knowledge, we believe to be noxious and those which are considered 

 to be innocuous. If entomological workers are to be of the greatest possible 

 assistance to medical science, it is their duty to collect all available data about 

 all blood-sucking organisms. They will thus be fore-armed with knowledge of 

 inestimable value should any species, at the moment believed innocuous or only 

 under suspicion, become incriminated as a disease-carrier. 



The following paper will therefore be confined to the blood-sucking arthropods, 

 mainly Diptera, collected during the tour, with the exception of a few records of 

 biting flies taken on previous journeys in Northern Rhodesia, in 1904, 1905 and 

 1908. The great bulk of the collection was made during the writer's recent tour 

 on behalf of the Entomological Research Committee in 1910 and 1911. During 

 this period the greater portion of the three British Protectorates, Nyasaland, 

 British East Africa and Uganda, were visited, and portions of Northern 

 Rhodesia and German East Africa were traversed. 



In the course of this survey over 5,000 miles were covered with native porters, 

 exclusive of railway or steamer journeys. A very large collection of all forms 



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