INJURIES TO TREES. 



105 



Borers and I/ice. These sometimes cause serious injury, 

 but it is seldom practicable to combat them successfully. It is 

 generally better to avoid them by planting the kinds that are 

 least subject to injury from their attacks. Where lice are injuri- 

 ous, kerosene emulsion or strong tobacco water are good reme- 

 dies. In the case of small trees that can be easily inclosed in a 

 tent, the best remedy is tobacco smoke. 



Figure 23. White Willow windbreak seriously injured Iby successive 

 attacks of saw-fly larvse. A common source of injury to willows. 



Mice and Rabbits. Seedlings and small trees of some 

 kinds are liable to injury from rodents, such as mice and rab- 

 bits, which gnaw the bark near the surface of the ground, and 

 perhaps girdle the tree. They are most likely to do this when 

 the ground is covered with snow, for this furnishes them with 

 a protection under which they can do their mischief without 

 fear of being molested. In the case of small seedlings such 

 injuries may be largely prevented by plowing a furrow or set- 

 ting boards on edge around the seed bed. If, after each snow- 

 fall, the snow is trodden down so as to make a solid path 

 between the seedlings and the grass or woodland whence the 

 mice come, they will be kept out, as they will not try to work 

 through the solid snow. Seedlings that are badly girdled in 

 winter should be cut off at the surface of the ground, to encour- 

 age sprouts from the roots. To prevent the gnawing of larger 

 trees, paint the trunks with a cement or lime wash made rather 



