117 



" During the latter part of August the laboratory was raided during 

 the night by hordes of a red driver-ant. These climbed the bottles in 

 which the tsetse-flies were kept, bit through the gauze, and, entering, 

 destroyed every fly. The bottles in which the pupae were kept were 

 also entered, but the pupae were not damaged. A still active larva 

 also, curiously enough, escaped injury. This incident is not recorded 

 as suggesting that driver-ants are enemies of the flies in nature, but as 

 a record that the larvae and pupae are not destroyed by these insects." 

 As regards natural enemies of G. morsitans in Nyasaland, the 

 following is extracted from a paper by Dr. W. A. Lamborn (82), 

 published in 1915 : " 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. 



" In mid-December, however, a Bembex was actually seen to seize 

 a tsetse-fly and to carry it away. The particular species had been 

 repeatedly observed buzzing round as I walked, but little attention 

 was paid to it at first, seeing that an inquisitive disposition seems to 

 characterise many Sphegid wasps. Then one of the insects was seen 

 to make a rush at a tsetse-fly on my leg, which it failed to secure. 

 When a goat was led through the district three more were seen in the 

 course of half an hour, after flying round and round the animal and 

 hovering a few feet away, to rush at tsetses on it, two unsuccessfully, 

 but the third was captured on the wing, having seized one of the flies. 

 So far, all attempts to find out the other habits of the insect have failed, 

 though the matter is receiving attention." It is worth noting that it 

 was likewise stated by Dr. E. Roubaud (1190) in 1911 that in Dahomey 

 G. longipalpis is attacked by large Bembex, which are found exclusively 

 in the zone infested by this species. When introduced into a long 

 glass tube with a live tsetse, one of these wasps quickly attacks the 

 fly and paralyses it with its sting. On the Congo Dr. Roubaud was 

 informed by certain Europeans that they had seen wasps, doubtless 

 belonging to the genus Bembex, darting at tsetse-flies and carrying 

 them off. 



Reference may also be made to remarks by Dr. G. D. Hale Carpenter 

 (25) on insect enemies of G. palpalis var. fuscipes in Bugalla I., Lake 

 Victoria, Uganda. Writing of the dragonfly known as Cacergates 

 leucosticta, Dr. Carpenter says : " This is an extremely abundant 

 species, and if one walks along the shore one is at once surrounded by 

 a crowd of these insects, some flying backwards in front of one as one 

 walks, and all apparently on the look-out for Glossina, which they 

 frequently attempt to catch ; and on several occasions they have been 

 seen to do so. 



" On one occasion in the early morning a young hippo was on the 

 fly beach, and I was able to approach closely enough to see with glasses 

 numbers of Glossinae on its flanks and buzzing round it. Very many 

 dragonflies were in attendance, and could be seen darting at the 

 Glossinae, and I have no doubt that they account for a certain number 

 of full-fed flies which are relatively heavy on the wing." 



As to robber flies (Asilidae) Dr. Carpenter says : "The powerful 

 and very active predaceous flies of the family Asilidae might be expected 

 to be important enemies of Glossina, since their appetites are apparently 

 insatiable and they prey upon insects of all kinds, even the most active 





