397 



126, iv). The anterior transverse vein is very oblique. 

 The bend in the course of the fourth vein, before it 

 meets the anterior transverse vein, is absolutely 

 diagnostic. 



Fig. 126. Wing Venation of Glossina, and antenna with 

 Feathered Arista. (After Austen) 



LlFE-HlSTORY 



Tsetse flies are not found far from water. They 

 frequent areas of thick wood or undergrowth, and are 

 not found in open spaces or clearings. As a rule, 

 tsetses and big game are found together, but there 

 appear to be exceptions to this rule.* They have a 

 great dislike for excrement of animals. 



Tsetse flies do not lay eggs, but yellow-coloured 

 larvae. These have been found among the roots of 

 banana trees. After a few hours these change into 

 pupae. The pupa is about six mm. long and three mm. 

 broad, and consists of twelve segments. The twelfth 

 segment is produced into two large lips, enclosing a pit, 

 the site of the respiratory stigmata in the larva. These 

 lips differ in shape and size in the different pupae. At 

 the anterior end is a longitudinal groove, through which 

 the fly eventually emerges in about six weeks. 



Structure of the Proboscis. The cutting mechanism 

 of the proboscis is formed by the labella, the inner 

 surface of which is provided with a number of fairly 



* Gl. palp alts feeds principally on crocodiles (Koch). 



