FOES AND FRIENDS OF THE PLANT 199 



beetles begin to feed on the leaves. Then they lay eggs 

 and disappear. Deep cultivation about the vine may de- 

 stroy many of the pupas. The beetles may be killed by a 

 strong arsenical spray, or caught by jarring them from the 

 vine into a cage. (California Experiment Station, Bulletin 

 195.) 



ANTS AND BEES 



Ants and bees are the most wonderful insects we know. 

 In a hive of bees or a nest of ants all work together for 

 each other's good in a way which we cannot but wonder at. 



They have queens which they guard with the greatest 

 care, and workers which do all kinds of work. They 

 divide up the labor of the nest or hive, each worker 

 doing its share and attending to its own work. 



Ants. Some of the ants have special police or sol- 

 diers; these are larger than the workers and have power- 

 ful jaws for fighting. Some ants capture the young of 

 other kinds and bring them up as slaves. Some kinds 

 plant garderis and harvest cropsL Others are hunters 

 and, marching together in great numbers, may even kill 

 and devour animals as large as cows. 



Many kinds of ants take care of plant lice, and by 

 stroking them make them give out drops of a sweet 

 liquid. This is known as milking, and the plant lice 

 are sometimes called " ant cows." The ants protect 

 them and take care of them much as we do of our 

 domestic animals. In Central America the acacia tree 

 produces a sweet substance which serves for food and 



