44 PARASITES OF THE DOMESTIC ANIMALS 



four to forty-eight hours. It is necessary, therefore, to regularly repeat 

 the application if the animals are to be continuously protected. Re- 

 pelling agents are best applied in the evening when cattle are stabled or 

 yarded. 



Tsetse Flies 



Genus Glossina. — Muscidae (p. 37). The tsetse flies (Fig. 24) are 

 about the size of house flies, or may be somewhat larger. The general 

 color is light brown. When at rest the proboscis projects in front of the 

 head. At the base of the proboscis is a bulbous enlargement, arista 



Fig. 24.— Tsetse fly. 



plumose above. The resting wings are folded scissors-like over the back. 



These flies are found only in certain areas in Africa. 



Glossina Palpalis. — Glossina (p. 44). This species is 8 to 9 mm. 

 (5/16 to 3/8 of an inch) in length. The color is brown dusted with gray. 

 The antennae are black. All segments in the hind tarsi are black. The 

 fourth and fifth segments of the fore tarsi are black. The halteres are 

 white. 



Glossina Morsitans. — Glossina (p. 44). About the same size and 

 color &8 G. palpalis. The antermae are dark. The first three segments 

 of the hind tarsi are yellow, the fourth and fifth segments black. The 

 fourth and fifth segments of the first and second pairs of tarsi are black. 



Glossina longipalpis is a species which in characteristics and distribu- 

 tion is almost identical with G. morsitans. 



Breeding Habits and Habitat. — The Glossina deposit hatched larvae 

 among roots of tropical vegetation. When deposited the larvae are well 



