﻿304 P. A. NEAVE — NOTES ON THE BLOOD-SUCKING 



starvation, took place in the Transvaal. I have been personally acquainted with 

 the Luangwa Valley from time to time during nearly nine years and the one 

 animal which shows an undoubted increase is the greater kudu, which, as is well 

 known, suffered severely from rinderpest. 



Under these abnormal conditions G. morsitans seems to have extended its 

 range during recent years to areas suitable to its existence and in which it 

 formerly occurred. In these special circumstances I am somewhat inclined to 

 think that the game has been a factor of some importance. It is not unreason- 

 able to conclude that the general scattering of game at the beginning of the 

 rains, from the limited area near water which they have frequented during the 

 dry season, has somewhat accelerated this spread of the fly during recent years. 

 This could not probably have happened but for these special circumstances, in 

 which there were adjacent areas suitable to the fly and unoccupied by it — a state 

 of affairs which would be very improbable under normal conditions. The fly has 

 apparently now nearly, if not quite, recovered all its lost ground, i.e., its present 

 distribution is approximately the same as before the advent of the rinderpest. 

 It will be of extreme importance to note whether G. morsitans now spreads into 

 areas which it did not occupy before the rinderpest, e.g., parts of Angoniland 

 where the natives have kept large herds of cattle for several generations ; 

 but it seems to me that this is very unlikely. It will thus be seen that it is 

 possible that some of the observers in Nyasaland and Rhodesia have been 

 unintentionally led to exaggerate somewhat the importance of game as a factor 

 in the distribution of G. morsitans by the above mentioned circumstances. 



With regard to the relations of this species with man, though, as is well known, 

 it bites man readily, I think it is doubtful whether it has any preference for him 

 as compared with other mammals. Indeed it is questionable whether this is true 

 of any species of Glossina, with the possible exception of G. palpalis. It has 

 often been stated that G. morsitans avoids human habitations, though many 

 observations as to the fly entering native villages have been made. This insect, 

 without question, frequently follows bands of natives traversing main roads into 

 the heart of villages, but it is doubtful if any but an occasional individual 

 remains there any length of time. I am in complete agreement with the views 

 expressed by Sir Alfred Sharpe and others that it is the cleared and cultivated 

 area that usually surrounds native villages which is the deterrent and not the 

 actual human habitations or their accompaniments. 



It Avould therefore seem that this species is only to be exterminated by exten- 

 sive occupation and cultivation by human beings of the area it occupies. This 

 area must be kept cultivated, as it seems probable that not only G. morsitans but 

 G. pallidipes will return to land where the bush has been allowed to grow up 

 again. Measures for clearing the bush and thus removing the natural cover, 

 as is being done in the case of G. palpalis, would seem impracticable. The 

 habitat of the insect is so different and its range usually so much wider, that a 

 road, for instance, through a fly-belt, to be efficiently cleared, would have to be 

 perhaps as much as a mile wide. Possibly something might be done in this 

 direction by imitating the condition surrounding native villages and planting 

 extensive strips of crops, such as sweet potatoes or ground-nuts, by the road-side. 

 It would seem probable that such low-growing crops would be a greater 



