CHAPTER V 

 THE DIPTERA OR FLIES 



The true flies or Diptera are, as the name implies, two- 

 winged insects, although they have what really corre- 

 sponds to the hind pair of wings of other insects in the 



FIG. 31. Head of housefly. (After Herms.) 



small club-shaped halteres or balancers which are joined 

 to the sides of the metathorax. All of the flies have 

 sucking mouth parts which include in many cases slender 



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