INJURIES TO TREES. 105 
Borers and Lice. These sometimes cause scrious 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 |by successive 
attacks of saw-fly larvee. 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 
