﻿236 LL. LLOYD — NOTES ON GLOSSINA MOKSITANS, WESTW., 



rising to feed and of the accompanying males thus finding mates. When the 

 animal stands there is little chance of females rising to it and this may be the 

 reason why the males leave. Mating couples have several times been seen on 

 the backs of natives. 



Food. 



Owing to the difficulty of obtaining suitable mammals, native fowls were used 

 almost entirely as blood donors for the captive flies. The small numbers of 

 pupae obtained would seem to indicate that fowls' blood is not a very suitable 

 food. This is perhaps because the blood forms large firm clots in the sucking 

 stomachs of many of the flies. When the blood has attained this condition it 

 cannot apparently be utilised by the flies, as the clots persist for some weeks 

 after the meal on fowls, though monkeys may have been used as food in the 

 interim. When such a clot is formed it would be impossible for the fly to retain 

 a full-grown larva in the uterus. The phenomenon has not been observed with 

 mammals' blood, nor has it been observed in nature. 



No evidence has been obtained that the flies take any food other than blood. 

 Out of sixty -seven freshly caught flies that were dissected, mammalian blood was 

 recognised in fifteen, nucleated red cells in four ; one fly contained both nucleated 

 and non-nucleated red cells ; in thirty-two, blood in a more or less digested 

 condition was seen ; while fifteen had either not fed or the detritus was not 

 recognisable. 



It seems possible that a little water may be taken, as the flies have been 

 observed at the edges of puddles and apparently drinking. Kinghorn has 

 observed the same thing with G. palpalis on the shores of Lake Tanganyika. 

 If a moistened sponge or blotting paper is placed in a bottle with captive flies, 

 they will settle on it and thrust in their proboscides. I have not been able to 

 prove by supplying coloured fluids and subsequently dissecting the flies that fluid 

 is actually absorbed. Exactly the same thing was observed with slices of ripe 

 water melon but again it could not be demonstrated that food was taken up. 

 Flies placed in bottles with Sphingid larvae died of starvation and were never 

 seen to take anything but the most perfunctory interest in the caterpillars. 



A gecko which was placed in a cage of flies caught and devoured the insects. 

 Experiments were also made with a monitor which was placed in the double 

 bottom of a cage made of gauze in such a manner that it was incapable of move- 

 ment. The flies in the cage attempted to feed but only one succeeded in doing 

 so, thrusting in its proboscis in the region of the head. The animal was 

 then killed and a cut section was offered to the flies, when several readily 

 gorged themselves. 



Enemies. 



An Asilid fly was taken on the wall of the laboratory devouring a tsetse-fly * 

 it had made a wound in the side of the thorax. The favourite food of these 

 rapacious insects seems to be Tabanidae, especially the larger species. One was 

 taken eating a dragon-fly. 



