96 



THE DESTRUCTIVE AGENTS OF FORESTS. 



' ' ( 5 ) By the utilization of a knowledge of the principles 

 of natural control as a means of contributing to the efficiency 

 of artificial control. 



"(6) By prompt recognition of the first evidence of the 

 work or destructive outbreaks of the principle insect depreda- 

 tors, by authentic identification of the species involved, and by 

 prompt action in adopting the proper method or methods of 

 control for the prevention of losses. 



''It should be remembered that as a rule it is useless to 

 attempt the extermination of an insect enemy of the forest or 

 its products. It is only necessary to reduce and weaken its 

 forces at least 75 per cent, so that it can not continue an ag- 

 gressive invasion, but must occupy a defensive position against 

 its own enemies and become dependent upon favorable condi- 

 tions resulting from avoidable negligence and mismanagement 

 by owners of the forests and the manufacturers of forest pro- 

 ducts. 



' ' While beneficial insects, beneficial birds, and beneficial dis- 

 eases exert a continuous and powerful influence toward the pre- 

 vention of a more extensive waste of forest resources, it has 

 been repeatedly demonstrated that they can not be depended 

 upon always to prevent widespread devastation or otherwise to 

 work for the best interests of the private or public owner by 

 protecting the best trees and the best tree species. 



"The best way to utilize the factors of natural control is 

 to become their allies and assist in the reduction of the enemy, 

 rather than to try to make them our allies through artificial in- 

 troduction or dissemination. 



"A large percentage of the waste caused by insects can be 

 prevented by the utilization of infested material, and at the 

 same time, without additional expense, this will contribute 

 greatly to the control of insects which cause such waste and 

 also prevent injuries and depredations in the future. 



"Under past conditions the poor management or neglect 

 of the average forest has contributed to the increase of depre- 

 dations by forest insects. 



"Under present conditions of better management of local 



