102 



^ ,Jth$ir r&tker" 'Complicated social scheme, makes one hesitate to reject 

 '1 .4K ^tferriative view. Lamborn (Bull. Ent. Res. vii, 1916, p. 37) has 

 argued well for the view that it need not be a large game population 

 that will support fry . . . . 



" In a relatively clean-stemmed area like that on the granite-gneiss, 

 in which also bush-pigs are not over-abundant, it is to me very con- 

 ceivable that wholesale game destruction might banish the fly. An 

 obstacle, however, would be that the whole territory is one vast game 

 area, so that the game would pour again into a given section of it as 

 soon as the persecution was relaxed unless an effective barrier were 

 created such as could probably only be made a permanency with settle- 

 ment behind it. Whether the returning game would bring the fly in 

 again would depend on (1) whether the whole continuous fly area had 

 been cleared of fly, or (2) whether the portion cleared had been split 

 off from the uncleared portion by an effective barrier against the 

 fly itself. 



" West of the Sitatongas the country is much more jungly, and 

 wholesale game destruction is proportionately more difficult In 

 addition this country abounds in bush-pigs, which are difficult to 

 destroy, and which in anything approaching their present numbers can 

 probably alone support the fly, with baboons, abundant cane-rats and 

 other animals, which may all contribute to its sustenance. I consider 

 that it will be impossible to starve the fly at all generally by ordinary 

 game destruction here, at any rate before the country is very fully 

 settled, though buffalos and elephants might be banished by adequate 

 and persistent shooting. 



" What can be done is to protect particular places, like Spungabera 

 and the British border, that are outside the fly, and are threatened only 

 by the wanderings thence of the bigger game. Fencing, the judicious 

 placing of native kraals, and shooting are amongst the possible measures, 

 and organised and repeated drives might be undertaken locally. I 

 have suggested similar means of keeping the fly from being carried 

 into any areas that may in the future be settled. 



" Again, it seems to me that game destruction should check the 

 advance of a fly-belt, whatever its effects on the ground already infested. 

 No problems are at present better worthy of study than these (1) the 

 extent to which tsetses will travel independently of game, and (2) the 

 distances that the female will travel on game." 



In 1918, a number of suggestions for checking the spread of G. 

 morsitans and trypanosomiasis in the Wankie district were made by 

 the Government Entomologist of Southern Rhodesia (18). While some 

 of these proposals were, for various reasons, admittedly either imprac- 

 ticable or inadvisable, it was thought that a properly organised attack 

 on the whole area invaded or threatened by the fly would have an 

 excellent chance of success. It was stated that this idea would involve 

 the wholesale extermination of game, first around the boundaries of the 

 affected area and gradually towards the centre, and that such an 

 undertaking appeared both feasible and economically sound. Destruc- 

 tion of winter haunts in threatened areas was likewise recommended, 

 it being suggested that since the fly is dependent during the time that 

 the trees are leafless upon evergreen trees in the vicinity of watercourses, 

 the removal of such trees would probably render the locality unsuitable 

 as a permanent fly-belt. 



Subsequently (17) it was resolved by the Government of Southern 

 Rhodesia to give effect, at least experimentally, to both of the foregoing 

 proposals. As regards the former of these, itVas decided to take steps 



