8 J. W. SCOTT MACFIE — THE DISTRIBUTION OF GLOSSINA 



investigate the distribution of the tsetse-flies in greater detail, and the results 

 obtained in this district might, I think, be considered to apply to the whole of 

 the great central plain of Ilorin. 



G. palpalis and G. tachinoides were the only species noted in this division. It 

 was seldom that a distinction could be detected in the haunts of these insects, 

 both being widely distributed over the country, and both, as a rule, occurring 

 beside the streams wherever the conditions were favourable. In some places, 

 however, there was a difference, as, for instance, on the Weru River where it is 

 crossed by the road from Paiye to Ilorin (PI. II, fig. 1). Here, after taking 

 several specimens of G. palpalis in the river-bed, I returned to my horse, tethered, 

 as I hoped, out of harm's way in an open space some distance from the river, 

 only to find him tormented by a dozen G. tachinoides which were biting at his 

 fetlocks. 



Nowhere in this division were the tsetse-flies sufficiently numerous to be a 

 scourge ; and this fact alone, whether it be due to the denser population and the 

 greater proportion of agricultural land or to some difference in the vegetation, 

 constitutes a remarkable contrast to the conditions obtaining in the eastern and 

 southern divisions. It is, moreover, noteworthy that in crossing the uninhabited 

 district to the north-west of the River Weru, I did not discover tsetse-flies until 

 the River Iwa was reached, although the vegetation was of the type that is 

 generally frequented by G. submorsitans, and the district was reputed to be well 

 stocked with game (PI. II, fig. 2). 



In spite of the general occurrence of tsetse-flies, numerous herds of Fulani 

 cattle are seen throughout the greater part of the western division, and appear to 

 thrive there. Moreover, it would be a matter of no great difficulty to render the 

 roads almost everywhere comparatively free from tsetse-flies, owing to the 

 relatively small numbers of these insects and the strict localisation of their haunts. 

 This step is an essential preliminary to the opening-up of the country and the 

 introduction of animal transport, as the following incident proves. In June 1912, 

 I undertook, at the request of the Resident, to locate the tsetse-flies on the road 

 from Ilorin to Agugi, along which it was proposed to try an experiment with 

 donkey transport. The road, which runs almost due east from Ilorin, is about 

 thirty miles in length, and traverses country which is overgrown by grass, and 

 dotted with scattered trees. Where there is a sufficient depth of soil above the 

 rocks, and in the river valleys, numerous farms occur, planted mainly with yams, 

 maize, and ground-nuts ; and at several places, as, for instance, around Iliapa, 

 Balogun, and Agugi, herds of cattle graze. Only at a few points does the road 

 pass through patches of orchard land, and, except on the river-banks, there is 

 between Ilorin and Lalenka no cover sufficiently deep to form a haunt for 

 tsetse-flies. The road crosses three rivers — the Oyun, the Oshin, and the Oyi — 

 and a number of lesser streams, tributaries of these. The banks of all the streams 

 are narrowly fringed with trees and undergrowth which in most cases harbour 

 tsetses, although the depth of the fringe is never more than a few yards. Tsetses 

 were taken on the banks of each of the three main rivers near the points where 

 the road crosses them ; they were also taken on one or more of the tributaries of 

 each. The species was in every case G. palpalis ; but at one river — the Oyun — 

 G. tachinoides was found in addition (PI. I, fig. 2). Under these circumstances 



