﻿AND HABITS OF GLOSSINA FUSCIPES IN UGANDA. 57 



The most favourable environment for the fly in this Province consists of the 

 conjunction of a tree- or scrub-shade, water, and a rocky clean bank. They are 

 often very numerous on rocky promontories, the vegetation on which offers the 

 very modest shade lent by creepers, tufts of grass, and scattered, very low scrub. 

 They are also very common on bare rocks, but these have always been so 

 situated that access to typical tree-shade was available, and doubtless the flies 

 retired there. They seem quite as numerous near rushing rapids as near the 

 more peaceful waters. The streams of the Province have a fringe of small forest 

 or scrub on either side, for the most part continuous, but often with patchy grassy 

 intervals. It is only when very rarely a forest or banana plantation comes to the 

 water's edge that the tsetse range more than a few yards from it. They extended 

 throughout one such banana grove which I chanced to examine. 



In a semi-forest extending to the river bank and having numerous open grassy 

 patches they were found to range as far as I penetrated, which was about half-a- 

 mile. Large numbers of hippopotami and lesser numbers of other game traversed 

 this area. In another case, somewhat widely scattered clumps of bush were 

 found to harbour the fly for a distance of one to two hundred yards from the 

 river. These had no doubt in the first place attached themselves to hippopotami 

 and then abandoned them for the shade of the trees, and being unwilling to face 

 the comparatively long flight in the open to the next clump or the river bank had 

 become at least temporarily isolated. 



Flies have been taken in a village a mile and a half from the nearest stream, 

 the intervening country being open, but undoubtedly in such cases they had 

 attached themselves to water-carriers or travellers. Nevertheless I do not think 

 these excursions are altogether comparable to those of palpalis on the Guinea 

 Coast, where they are described as infesting whole villages, roads, and large 

 sections of forest. In the Gold Coast I found the high forest-clad hills near 

 Berekusa (some 20 miles north of Accra) to be haunted by palpalis over a con- 

 siderable area. Many oil palms grew in this region. 



Where the irregularity of the rocks offers shady under-surfaces, these seemed 

 to me to be the favourite resting places. Less frequently the under surfaces of 

 leaves or small branches were resorted to. 



While rowing during a moderate rainfall at a distance of some 50 to 75 feet 

 from the Nile bank large numbers of fly kept boarding us. Some, instead of 

 seeking the shelter of the awning, hovered around sailors seated in the bow, being 

 entirely exposed to the weather's inclemency. This observation should, I think, 

 tend to moderate the generally accepted view of the rigorously inimical effect of 

 rain on their activities. 



During the dry season, when everything here is parched, I examined a number 

 of small stream-beds near watersheds (February). These were either dry or 

 consisted of a series of pools. In most cases no flies were taken. When these 

 water-courses were revisited in the wet season (June) tsetse were invariably found 

 right up to their immediate swampy sources. It seems to me that this would 

 point to a migration within limits. In the wet season too they have been observed 

 for considerable distances up sandy waterless stream-beds which could only 

 contain running water for a few hours after heavy rain. 



