47 



" (4) The flies do not usually travel higher than 4 or 5 ft. from the 

 ground, and probably never ascend as high as 10 ft. 



" (5) They probably do not feed on monkeys or birds, but on ground 

 animals, e.g., wart-hog, duiker, or bush-buck. 



" (6) The flies require a meal fairly frequently, and cannot withstand 

 starvation (without water) for longer than 24 to 30 hours. In cap- 

 tivity, at any rate, they will feed on the dead bodies of other Tsetse- 

 flies. I am inclined to think that they may feed naturally on other 

 insects, ticks, grasshoppers, etc. They certainly feed voraciously on 

 human beings. 



" (7) I am of opinion that, during the day, the flies are constantly 

 moving about from place to place within the fly-belt, i.e., in deep 

 shade, and only for short periods rest on the under side of twigs and 

 small branches, and perhaps on the ground." 



On the other hand, Dr. J. J. Simpson (142 III.), writing on the distri- 

 bution of Glossina in Southern Nigeria, remarks : " The conditions 

 which are most favourable for G. palpalis are, generally speaking, 

 most unfavourable for G. tachinoides. Where the country is open, 

 the vegetation sparse, the dry season well defined and the rainfall 

 slight, there G. tachinoides is most abundant. Consequently, this 

 species is the predominant one in the region bordering the Sahara 

 in Northern Nigeria ; it is the only member of the palpalis group found 

 in the Lake Chad area." 



Simpson's statements are corroborated by Roubaud (I23a), who>, after 

 stating that the partiality for the immediate proximity of water 

 displayed by G. palpalis is exhibited in equal degree by G. tachinoides, 

 continues : " This species, however, as I have mentioned elsewhere, 

 possesses greater resistance to heat than does G. palpalis. This 

 resistance, which may exceed a mean of 35 C. [95 F.], enables it to 

 exist in a more northerly habitat. Thus it is G. tachinoides rather 

 than G. palpalis that is met with in the belts of thin forest fringing 

 the Soudanese rivers (forest belts of the Soudanese zone of A. Chevalier), 

 where the temperature is subject to much greater variations than is 

 the case in true forest belts. It is not uncommon, in the shade of 

 strips of woodland infested by G. tachinoides, to find the temperature 

 of the air during the day exceeding 30 C. [86 F.]. 



" This fly, which is the smallest of the Tsetses, is also the most active,, 

 and the quickest in its movements and biological manifestations. 

 It is likewise an insect which, more exclusively than G. palpalis, 

 derives its sustenance from wild animals. Unlike the species men- 

 tioned, it is scarcely ever found permanently established in the vicinity 

 of villages ; on the contrary, it displays a predilection for sparsely 

 inhabited regions full of game, where there is abundant animal food at 

 the water's edge." 



" In Southern Arabia, G. tachinoides was found by Captain R. M. 

 Carter sparsely and locally in thick belts of euphorbia, babal thorn 

 and tamarisk, and also in cactus belts. It was never seen ' in the 

 date groves or along patches of cultivation,' and was not always met 

 with near the edge of water " (Austen). 



Glossina austeni, Newst. Writing of this species in his " Notes on 

 the Blood-Sucking Insects of Eastern Tropical Africa" (1912), Dr. 

 S. A. Neave (103) says : " It occurs in company with G. pallidipes 

 and G brevipalpis, though it seems to require more heavily forested 

 country than that in which those species sometimes are found. It would 



