What Are the Enemies of the Trees? 109 



a loss of many millions of dollars every year. Among the 

 worst of these is the San Jose scale, which was carelessly 

 brought into the country from China. 



The pear blight has destroyed whole orchards of pear 

 trees in the Western states. The citrus canker is now 

 threatening the orange orchards of the Southern states. 



For years we have been searching over the world for new 

 and better varieties of fruit trees. With the shipments 

 of such trees we hsxe brought some of the worst of the dis- 

 eases that we have just mentioned. We should have all 

 foreign trees most carefully inspected before admitting 

 them to the country. We should also be ver}- careful about 

 shipping fruit or other trees from one part of oiu- country 

 to another. Diseases are often carried in this way into 

 places which otherwise they could not reach. 



Field mice, gophers, and rabbits eat the bark of young 

 fruit trees and kill those which are not carefully protected. 

 In some parts of our coxmtry the apple and peach tree 

 borers are a serious menace to young orchards. Grass- 

 hoppers occasionally come in dense swarms and eat the 

 leaves from e\'ery tree or plant in their path. 



The valuable sugar pine of the Western mountains is not 

 seeding itself as rapidly as it should, and we fear it will be- 

 come extinct. The beautiful silver-gray squirrel loves the 

 nuts of this pine, and it is said that he eats so many that 

 few are left to sprout and make new trees. For this reason 

 some people would like to make it lawful to kill all the gray 

 squirrels that one wished. This would be too bad, for we 

 do not believe the gra\- squirrel is the cause of the trouble. 

 It is more likely that the lack of young sugar pines is due 

 partly to. its struggle in the forest ydih. more rapidly grow- 



