39 



places and salt licks. While 123 of the breeding places, yielding " less 

 than ten pupae each," were " scattered generally through the bush 

 with no special relation to the paths," the spots in which pupae were 

 found in by far the greatest numbers showed unmistakable relationship 

 to the latter. " Over 50 and under 150 pupae," writes Mr. Lloyd, 

 " were found in 13 positions which yielded 892 pupae, an average of 

 68 5 per position ; these positions bear a very close relation to the 

 paths, nine of them being within a yard, and the remaining four being 

 less than 100 yards from a path." 



The following is an extract from a summary of a report (50) by 

 another entomologist (the late 2nd Lt. R. A. F. Eminson, K.R.R.) 

 upon work done by him in investigating the bionomics of Glossina 

 morsitans in Northern Rhodesia, from May to July 1914 : : 



" In the course of his remarks on breeding places Mr. Eminson 

 states that he has not yet succeeded in ascertaining definitely why 

 certain spots are specially preferred by G. morsitans for breeding 

 purposes ; but two negative points are noted, namely, that in country 

 otherwise suitable, no favoured breeding places have been found in any 

 localities in which there was any depth of sandy soil, or in which there 

 was a dense growth of long grass. Although a search was made for 

 pupae over a considerable area, the great majority were found within 

 a comparatively restricted space. This favoured area is described as 

 being ' uniformly covered with forest trees ; very little grass grows 

 amongst the trees, and that little is short ; the soil is of a sandy, 

 gravelly nature and very thin, merely covering the underlying granite 

 which crops out in places. The surface of the ground shows a gentle 

 slope in a north-westerly direction to a vlei [open, moist, low-lying 

 land] in which a little water stands in the wet season, but which is 

 completely dry at this season [mid- winter] . I cannot say that I have 

 noticed much spoor of game, except some impala and wart-hog ; 

 certainly I should not say that there was any more game than in the 

 surrounding country, if as much. The breeding places which yielded 

 the greatest number of pupae and empty pupa-cases were situated near 

 the path ; the fly had evidently been feeding on game, or more probably 

 human beings, preparatory to depositing their larvae/ 



" It is noted that many of the logs under which large numbers of 

 pupae were found were devoid of bark, and, in Mr. Eminson's opinion, 

 the female tsetses prefer a smooth barkless log on which to rest before 

 depositing their larvae. They also show a preference for a log which 

 in some part of its length is raised a few inches above the ground, thus 

 affording a shady resting place ; a point which has already been 

 emphasised by Mr. Llewellyn Lloyd." 



Writing in 1915 on G. morsitans breeding places in Nyasaland, Dr. 

 Lamborn (83) says : " Until April the search for breeding places had 

 been almost without result, five pupae only having been found in hard 

 clayey soil. But since then they have been obtained in large numbers, 

 as the result of realising that the condition of the soil is one of the all- 

 important factors in determining whether or not a particular spot 

 will be selected by the female. 



" As pointed out by Mr. Lloyd, the fly seeks some relatively dark 

 and shady spot. Many such are to be found in a tsetse area, mostly 

 under fallen trees ; but in my experience, which is now considerable, 

 being based on an examination of 512 breeding places, few, if any, 

 pupae will be found unless, in conjunction with the shelter, the soil 

 is likely to be dry at all seasons, having no hard top crust, such as is 

 formed under the influence of moisture and sun, and containing sand 



