254 GLOSSINA TACHINOIDES [CH. 



Although usually confined to the vicinity of water, in 

 Southern Arabia G. tachinoides occurs in thick belts of euphorbia, 

 tamarisk and cactus, often some distance from the edge of 

 any water, but is never seen in the date groves or along the 

 patches of cultivation. 



Moiser has recently given an interesting account of the 

 habits of G. tachinoides in the Bornu Province, Northern Nigeria, 

 where the flies have existed for an indefinite period confined to 

 the thick bush. In order to study the vertical range of the 

 flies, men were posted up trees at heights varying from lo 

 to 25 feet, but in no case were any of the insects seen, 

 although there were several on the ground. As a result of his 

 observations Moiser comes to the following conclusions : — 

 Deep shade and proximity to water appear to be the main factors 

 influencing the distribution of the flies. Their natural resting 

 place is on the lower side of twigs and branches of undergrowth, 

 under the shade of large trees, at a height usually not greater 

 than a foot above the ground. The flies are very restless and 

 the observer is of the opinion that during the day they are 

 continually moving about from place to place within the fly- 

 belt and only for short periods rest on the under surface of 

 twigs and small branches and perhaps on the ground. They 

 do not usually travel higher than four or five feet and probably 

 never as high as ten feet, therefore it is unlikely that the flies 

 feed on monkeys or birds, but on the ground animals, e.g. the 

 warthog, duiker or bushbuck. 



G. tachinoides requires a meal fairly frequently and accord- 

 ing to Moiser cannot withstand starvation without water for 

 longer than 24 to 30 hours. On the other hand Roubaud 

 kept ten flies in saturated air and all were alive after three 

 days, and three after ten days. In captivity they will 

 feed on the bodies of other tsetse-flies and it is not improbable 

 that in nature they feed on other insects, ticks, grasshoppers 

 etc. Certainly in Arabia, Carter noticed this fly in localities 

 where the chance of getting a feed of mammalian blood must 

 be very slight indeed. The flies feed voraciously on human 

 beings and are very troublesome, as they are quite active in 

 dull weather and in the very early hours of the morning, when 



