﻿TACHINOIDES, NEAR GEIDAM, BORNU PROVINCE, NORTHERN NIGERIA. 201 



whereas most of the flies in the wet bottle lived for three days, and the last fly lived 

 till the morning of the 3rd Jan., i.e., four complete days, without any food whatever. 



In connection with this, it is interesting to note that I was told by a native of 

 Jigaje that tsetse-flies are in the habit of settling on the mud, when the river is 

 low, and inserting the proboscis to obtain water. I saw this occur several times 

 in the wet bottle, but did not observe anything of the kind on the river bank, 

 which I watched carefully for some hours ; there was, however, plenty of water 

 in the river close by. 



6th Jan., 1912. — River Wobe, near Abari, about 6 miles E. of Geidam. I 

 crossed to the north bank of the river in the early morning, and spent the day in 

 examining the bush for tsetse. I found four separate and distinct localities occupied 

 by the flies, all being G. tachinoides . None of these belts were close to the river, 

 but bordering on marshes about one-half to one mile north of the river. In each 

 case the flies were congregated in patches of thick shady bush, with a consider- 

 able amount of undergrowth, and they were peculiarly confined to these small 

 areas, the intervening open bush being free from them. The chief trees were 

 tamarinds, ebony trees and thorns. The animals seen were warthog, monkeys, 

 gazelle, bushbuck and reedbuck. 



In every instance there was standing water in close proximity. I noted a few 

 flies resting on the under side of small twigs and branches close to the ground. 

 I did not observe coitus to take place, but some of the females caught were 

 certainly pregnant. The soil was dark fissured clay, covered, in the dense 

 patches of bush, with humus and debris of twigs and leaves. As usual, the flies 

 did not follow us far into the bright sunlight. 



A clearing experiment with Glossina tachinoides. 



The following is an account of an experiment carried out in the fly-belt near 

 Bellaram, referred to above {see Map), the object of the experiment being to see 

 if the cutting down of all undergrowth in the kurimi would get rid of the flies. 



The clearing of the undergrowth in the kurimi was commenced on 3rd Feb., 

 1912, starting from the west end, and working gradually eastwards. When about 

 200 yards had been cleared, and the undergrowth piled into heaps, it was left to 

 become thoroughly dry till Feb. 19th, on which date the dried heaps were burnt, 

 and the ground thoroughly swept, all dried leaves and twigs being thus removed. 

 Meanwhile, on Feb. 15th and 16th, about 500 men were employed in cutting 

 down the rest of the undergrowth throughout the kurimi, and these freshly-cut 

 heaps were then allowed to become dry. 



Observations made on Feb. 17th, 19th and 20th, showed that the mere cutting 

 down of the undergrowth had made no material difference to the distribution of 

 the flies. They were still found in the same localities as before, and they did 

 not seem to have spread outside the kurimi. 



Of 49 G. tachinoides examined, 29 were males and 20 females ; of the latter 

 five were found to be pregnant. The larva was squeezed out of the abdomen in 

 each case, and it was found that in two the tumid lips were already black, these 

 being white in the other three cases. I failed to find any pupae in the soil or 

 amongst the debris of leaves ; nor did I see any flies go to the river to drink water. 



Twelve flies were dissected, and examined microscopically for the presence of 

 flagellates, but none were found. 



