GENUS GLOSSINA: TSETSE FLIES 377 



Thorax marked with Inconspicuous greyish brown stripes or spots. 

 Chaetotaxy (macrochaetae) : Humeral from I to 3, sometimes 4, the 

 lowest' bristle the largest ; posthumeral wanting; notopleural 2 ; presutu- 

 rffl 1 ; supra-alar I ; intra-alar I ; post-alar 3 ; dorsocentral 3, one anterior 

 to the suture and two posterior ; acrostichal I ; sciitellar 2 ; prothoracic I ; 

 stigmatic I ; mesopleural 6 ; pteropleural 3, besides several smaller ones ; 

 sternopleural 3, arranged I : 2. Abdomen yellowish to dark brown, con- 

 sisting of eight segments, seven only visible, the first being concealed 

 beneath the scutellum. Male hypopygium characteristic in shape 

 (see page 87). Wing venation characteristic, veins concentrated along 

 the anterior half of -wing; membrane rilled. The fourth longitudinal 

 vein is bent downwards in its basal portion, but about the middle of the 

 wing bends sharply upwards; in its apical portion it passes obliquely 

 downwards, again bending up to reach the margin of the wing some 

 distance anterior to the apex ; the second, third and fourth longitudinal 

 veins all turn upwards at their extremities. The anterior transverse vein 

 is very oblique. Reproduction larviparous, larva born -when ready to 

 pupate. Puparium with characteristic protuberances. 



The Glossininae or 'Tsetse flies,' as they are popularly called, are 

 next in importance to the Culicinae among the blood-sucking Diptera. 

 Through the researches of Koch, Bruce and his collaborators, Kleine 

 and his co-workers, and a host of others whose names are not so familiar, 

 it is known not only that Glossina palpalis and G. morsitans convey to 

 man by their bites Trypanosoma gambiense and T. rhodesiense, but 

 exactly how and under what conditions these flies can infect man. This 

 knowledge has been of fundamental importance in the fight against 

 Sleeping Sickness in Tropical Africa. In addition, several trypanosomes 

 which cause fatal forms of animal trypanosomiasis are known to be 

 transmitted by one or more species of Glossina. 



A fresh impetus has been given to the study of these flies owing to 

 the fear of the spread of human trypanosomiasis into South Africa, and 

 workers of all nationalities are now engaged in working out their life 

 histories and geographical distribution, and their relations to. human 

 and animal trypanosomiasis. Fortunately for man and his domesticated 

 animals, the tsetse flies, with one exception, (G. tachinoides, West.) are 

 only found in Africa. 



Owing to the importance of these flies it is necessary to give a some- 

 what detailed account of every species. In compiling what follows 

 Austen's valuable and indispensable Handbook of the Tsetse Flies has 

 48 



