272 R. B. WOOSNAM — SEARCH FOR GLOSSINA ON THE AMALA 



belongs to a group of species which are more or less crepuscular in their 

 habits. It is possible therefore that this fly may continue its activities throughout 

 the night, in the same manner as G. pallidipes does in the coast regions of 

 British East Africa. From personal experience I can testify to the fact that 

 G. pallidipes feeds greedily during the whole night, bnt, in my experience, not 

 during the day-time. The possibility that the tsetse-fly on the Amala river 

 feeds principally during the night is borne out by the fact that I failed to 

 capture a single specimen during a whole day's search, as I shall describe 

 later ; but I was unable to search at night. 



While I was discussing the distribution of tsetse-flies with Ol-botor-ol-joni 

 and several other Masai from his village, one of my porters, who had all been 

 instructed to catch any flies which might bite them, brought me a large Tabanns 

 (probably T. ustus) which he had caught biting his leg. I showed the fly to 

 the Masai, and Ol-botor-ol-joni at once said that it was not a tsetse-fly 

 (Endorobo) ; some of the Masai present agreed with him, but others insisted 

 that it was a tsetse-fly. However, one of them, in order to settle the dispute, 

 volunteered to go and catch a tsetse. He went away and within half an hour 

 returned with a leaf folded up and tied with grass, in which he said there was 

 a tsetse-fly. I put the leaf into a killing bottle and in due course opened it, 

 and found inside it the only tsetse-fly which I obtained during the expedition. 

 This fly was caught at about 3.30 p.m. (I was able to spend only one whole 

 day in the fly-areas as I was obliged to return to meet His Excellency the 

 Governor at a certain time.) 



As soon as I saw this one tsetse-fly I asked its captor if he could show me any 

 more, which he said he was confident he could do. So I at once set out with him 

 and took with me a donkey and a very dark-coloured mule. We proceeded to 

 the bush along the course of one of the little streams near by, where I was 

 assured there were always tsetse-fly to be found, and where the one specimen I 

 obtained had been caught. I remained there from 4.30 p.m. until dark, moving 

 the mule and donkey slowly about among the bush and down the bed of the 

 stream, remaining stationary now and then for ten minutes. Not a biting fly of 

 any kind was to be seen, except Haematopota, Stomoxys, and Lyperosia. 



The next morning I started at about 8 a.m. with the mule and donkey, and 

 most carefully hunted several of the places where the Masai told me tsetse-fly 

 were always to be found. I failed to obtain a single specimen, although I 

 remained there until 4 p.m., when I was obliged to return to my camp 10 miles 

 up the river. Several other genera of blood-sucking flies were seen. A large 

 Tabanus, which I believe is T. ustus, was numerous, and Haematopota, Stomoxys, 

 and Lyperosia were seen and captured. A few specimens of Tabanns maculatis- 

 simus were seen, but they were very shy and only one was caught. One specimen 

 of the genus Chrysops was seen, but escaped. These blood-sucking flies all 

 appeared after 11 a.m., and at about 12.30 a.m. one single Glossina appeared and 

 settled low down on the mule's leg, but did not feed, and disappeared instantly, 

 although I made no movement to catch it, as I was anxious to allow the mule or 

 donkey to be infected if possible, in order to take the strain of trypauosome back 

 to the Government Laboratory at Nairobi, 



