25 



THE HICKOEIES. 



The hickories of lawns, parks, and forest, have suffered from time 

 to time within the past half century from the destructive ravages of 

 the hickorj' bark-beetle {Scolytus ^-spinosus) from Missouri to north- 

 ern New York and West Virginia. Recent investigations and exten- 

 sive experiments with felled and girdled trees indicate that this pest 

 can be controlled so that under a system of improved forestry manage- 

 ment little or no loss should result from its attack. 



The poplar, tulip, beech, birch, and, in fact, all of the principal 

 forest trees have their special insect enemies, which attack the living 

 trees and are more or less destructive to their lives or to the commer- 

 cial value of their timber products. 



DEPREDATIONS IN THE WOOD OF DYING, DEAD, AND FELLED TREES, 

 TIMBER PRODUCTS, CONSTRUCTION TIMBER, AND STORED PRODUCTS. 



In addition to the primarily destructive enemies of living forest 

 trees, there is a host of enemies of the wood of the dying and dead 

 standing and felled trees of all species, which cause serious defects 

 and rapid deterioration. Many of these injuries to the wood present 

 problems of great economic importance and most promising lines of 

 investigation in the possibilities of discovering simple methods of 

 preventing losses. 



Omistruction timiers. — There are a number of wood-boring insects 

 which attack and breed in heavy construction timbers, especially those 

 used for railroad ties and in culverts, trestles, and bridges. These 

 are not only weakened by the borings of the insects, but entrance is 

 given to wood-decaying fungi, which work so rapidly that, before it 

 is realized, certain parts may be rendered exceedingly dangerous. 

 Therefore, the relation of the combined effects of insects and fungi to 

 accidents from the collapse of buildings and railroad structures is a 

 subject of special interest and importance for detailed study. 



Stored forest products. — Insect depredations on stored forest prod- 

 ucts, such as tan bark, hickory handles, buggy spokes, and hoop poles, 

 is another problem coming within the range of forest entomology 

 which demands special attention. Recent investigations of insect 

 enemies of stored tan bark have revealed the fact that both oak and 

 hemlock bark are subject to attack by at least five species of insects, 

 which convert into fine powder the inner or flesh part of the bark 

 that has been stored over two or three years. As much as $70,000 

 worth of hemlock bark was found to be infested at a single tannery in 

 West Virginia, and personal investigations at other tanneries in the 

 State, together with information from other States, indicate that this 

 is a widespread trouble in the East and North and evidently extends 

 into Canada. 



