BITING FLIES. 



2 35 



The Tabanidae are not implicated as intermediate hosts in the trans- 

 mission of disease. By their bites, however, they may transmit disease 

 directly, as with anthrax. 



Muscidae. 



The common housefly, M. domestica, is the best example of this 

 family. This fly is incapable of biting, but may transmit disease 



\ 



7- oft. 



FIG. 73. Insects in which imago stage is important, i, Stomoxys calcitrans; 

 2, arista of Glossina palpalis; 3, Glossina palpalis (tsetse fly). 4, Tabanus autum 

 nalis. 



directly, carrying infectious material from the source, as in faeces, to the 

 food about to be ingested. Their role in typhoid fever is one of im- 

 mense importance. 



In the Muscidae the antennae hang down in front of the head in 3 

 segments, and have a plumose arista. There are no bristles on ab- 

 domen except at tip. 



