78 SOME INSECTS INJURIOUS TO FORESTS. 



quence a large percentage of the timber of the entire National Forest 

 has been killed. There were, then, no forcible examples of the prac- 

 tical value of such recommendations based on scientific research, and 

 no other argument was effective in arousing public interest in the 

 threatening character of the outbreak or confidence in scientific ad- 

 vice or methods of control. Now we have several examples demon- 

 strating the practicability of forest-insect control in America which 

 should lead to confidence in the results of scientific research as a basis 

 for success in practical application. 



Control of the hickory barkbeetle. — The complete control of the 

 hickory barkbeetle (Scolytus quadrispinosus Say), which threat- 

 ened the total destruction of the hickory trees on Belle Isle Park, 

 at Detroit, Mich., in 1903. was effected by felling and removing the 

 infested trees and converting them into merchantable products, all 

 without cost to the park commission. (Hopkins, 1904&.) 



CONTROL OF INSECTS WHICH CAUSE DEFECTS IN LIVING TIMBER. 



The class of insects which causes defects in the wood of living 

 timber can be controlled to a greater or less extent, depending upon 

 local conditions, and a large percentage of the losses prevented 

 through the adoption of certain requisite details in forest manage- 

 ment. Of these the following are especially important : 



(1) The utilization of all of the defective and infested timber 

 that will pay expenses for manufacture into merchantable products, 

 such as lumber, cordwood, etc. 



(2) The burning of infested timber and waste material not avail- 

 able for use, including dead standing and fallen timber, to remove 

 the breeding places of insects like the oak timber worm and the 

 chestnut timber worm, which go from the dead to the living timber. 



(3) The prevention of wounds of any kind in the bark of living 

 trees. 



(4) The prevention of future losses by the practice of improved 

 forestry methods which will eliminate favorable conditions for 

 injury and contribute to a perpetual supply of vigorous, healthy 

 timber to be utilized before it passes the stage of profitable increment. 



PREVENTION OF INJURY TO DYING AND DEAD TREES. 



A large percentage of the injury to the wood of insect, fire, and 

 lightning killed trees and those killed or dying from injuries by 

 storms, disease, etc., can be prevented as follows : 



(1) By the prompt utilization of such timber within a few Aveeks 

 or months after it is dead or found to be past recovery. 



(2) By removing the bark from the merchantable portions of the 

 trunks within a few weeks after the trees are dead (the work to be 

 clone either before or after the trees are felled). 



