356 



GENERAL SCIENCE 



(Figure 318). The adult fly breeds at once. Since the 

 whole cycle from egg to fly requires but two weeks, it is easy 

 to account for the large number of flies in late summer. 



Fortunately most of them are 

 killed by the winters of the 

 temperate regions. 



Insects form by far the 

 largest class of animals. 

 Some of them are valuable, 

 but many of them are de- 

 structive and live at the 

 expense of valuable plants. 

 Typical insects are the locusts 

 or short-horned grasshoppers, 

 the butterflies, the moths, the 

 beetles, the cicadse, the bees, 

 ants, and wasps. 



Bees and Ants. From 

 the social standpoint these 

 insects are very interesting. 

 They seem to have worked 

 out a scheme for community 

 life which provides for a gov- 

 ernment and a division of 

 labor (Figure 319). 

 The honeybee is the most interesting individual of 

 this class of insects. In their wild state honeybees 

 live in colonies with a hollow tree for a home. There 

 are three kinds of bees in a colony: the male bees or 

 drones, the workers, and the queen or female bee (Figure 

 320). If it is possible to have a hive of bees for observa- 

 tion, the division of labor may be easily seen and studied. 

 The queen's work is to lay all the eggs. This she does 



FIG. 318. The House Fly, Male 

 (top) ; Female (bottom). 



