REPORT ON GLOSSINA IN NYASALAND. 



G3 



of catching the flies attracted by the animal. The results were by no means 

 satisfactory, for no more than eight flies were taken, though the goat remained there 

 for 7 days, a failure possibly to be explained by its not being called upon to move 

 about with any degree of activity, and by the inability of the fly to see such movements 

 as occurred, my experience in this connexion confirming that of other observers, 

 namely, that the flies are attracted especially by moving objects. 



Why, however, the odour of the goat, which was especially strong, the animal 

 being a male, should have failed to attract them it is difficult to understand, seeing 

 that, like some Tabanidae, G. morsitans will after a little time discover a freshly 

 killed animal and settle to feed, in which case the fly can only have been drawn 

 to the scene by the sense of smell. When this particular goat was removed and 

 paraded up and down in the vicinity it was much assailed by the flies. 



A series of experiments was made in the use of English bird-lime spread on various 

 materials carried on the backs of natives, in the hopes of catching morsitans in the 

 same way as palpalis is caught in the Island of Principe. The results are tabulated 

 below : — ■ 



Date, 



Material used. 



8 Dec. 



9 „ 



10 

 11 

 12 



15 



16 



17 



18 



Deal board, 3 ft. by 3 ft 



Green cardboard, 3 ft. by 3 ft. . . 



>» »» jj >» • . 



Tarred waterproof paper, 3 ft. by 3 ft. 



Board made of dried bamboos laced 



together, 3 ft. by 3 ft 



Light brown paper, 3 ft. by 3 ft. 



Boys. 



Duration of 



experiment, j 



1 



a 



6 hours 



a 



» J 



b 







c 







a 







a 







a 







b 







a 







b 







a 







b 







a 







b 







a 







b 







Tsetses 

 captured. 



18 

 23 

 15 



39 

 17 

 29 

 12 

 7 

 53 

 59 

 58 

 67 

 31 

 54 

 51 

 47 



As morsitans is so frequently observed to settle on the underside of loads carried 

 on the heads of natives, experiments were also made in the use of material limed 

 on the underside carried in a horizontal position, but the results were not so 

 satisfactory as when the material was carried in a vertical position. 



Natural Enemies. 



Considerable attention has been devoted to the fossorial wasps of the genus 

 Bembex as being possibly natural enemies of morsitans, one species in particular being 

 especially numerous in the fly area. A long series of specimens, each taken on the 

 wing carrying its prey, shows that this species attacks in particular flies of the 

 families Asilidae and Bombyliidae. Several other species taking various 

 MusciDAE and Orthoptera have also been secured. 



