312 THE PRINCIPLES OF HANDLING WOODLANDS 



following year. It is, however, weakened, and continued 

 defoliations will ultimately kill it. The most conspic- 

 uous example of an invasion of defoliating insects is the 

 present outbreak of the gipsy and brown tail moths in 

 New England. Extensive wood-lots have been entirely 

 killed. The States, the Government, and the various 

 communities are spending hundreds of thousands of dol- 

 lars to check the depredations. 



Another illustration of the damage by defoliating 

 insects is seen in the outbreak of the larch-worm, which 

 has occurred in the Northeastern States within recent years. 

 In many sections SO to 100 per cent, of the mature larch 

 has been killed by repeated defoliations of the trees. 



Injury to Trees. — Certain classes of insects attack the 

 wood of living trees, but do not kill them. These in- 

 sects bore into the interior of the trees and seriously 

 affect the value of the lumber cut from them, often ren- 

 dering it useless. 



The damage done by the chestnut timber worm is well 

 known. In some sections practically every mature chest- 

 nut is more or less affected. Dr. Hopkins estimates that 

 the reduction in value of the lumber of chestnut amounts 

 to about 30 per cent on account of the attacks of this in- 

 sect. 



The locust suffers so constantly from the attacks of 

 the locust borer that foresters hesitate to propagate the 

 tree at all. Another example of damage by borers is 

 seen in the defects of white and rock oak, beech, yellow 

 poplar, and other hardwoods, resulting from the work of 



