318 



the higher grades to the consumer, and results in an increased drain 

 on the natural resources. 



The total value of the forest products of the United States in 

 1907 is given as $1,280,000,000; the losses from insect depredations 

 at 8% would represent an annual loss in a cash value of more than 

 $100,000,000. 



Reduction in Value of Finished and Commercial Products. 

 When we consider the aggregate loss to the manufacturers of the fin- 

 ished products, to the trade, and to the consumer from insect inju- 

 ries to the wood, it is evident that it amounts to many millions of 

 dollars in addition to the estimated loss of crude products, or at least 

 3 per cent of the mill value. 



METHODS OF PREVENTION AND CONTROL. 



The results of extensive investigations and of practical applica- 

 tions of the knowledge gained during recent years have demonstrated 

 that some of the most destructive insect enemies of American forests 

 and of the manufactured and utilized products can be controlled, and 

 serious damage prevented, with little or no ultimate cost over that 

 involved in forest management and business methods. 



There are, of course, certain insects and certain injuries which, 

 under present conditions and available information, can not be con- 

 trolled or prevented, but it is very evident that if the information 

 now available through the publications of the Department of Agri- 

 culture and through direct correspondence with its experts is prop- 

 erly utilized in the future it would result in the prevention of at least 

 30 per cent of the estimated annual waste of forest resources that has 

 been caused by insects within recent years, and thus contribute 

 greatly to the conservation of forest resources. 



GENERAL PRINCIPLES OF CONTROL. 



The ordinary spraying and similar methods employed in deal- 

 ing with fruit and shade tree insects are, of course, not available for 

 practical application in the case of forest trees. But there are other 

 and less expensive methods of accomplishing the desired results. 



In all efforts to control an outbreak or prevent excessive loss 

 from forest insects it should be remembered that as a rule it is useless 

 to attempt the complete extermination of a given insect enemy of a 

 forest tree or forest product. Experience has demonstrated that it 

 is only necessary to reduce and weaken its forces 75 per cent or more. 

 It can not then continue an aggressive attack, but must occupy a 

 defensive position against its own enemies until conditions resulting 

 from avoidable negligence and mismanagement by the owners of the 

 forests and manufacturers of forest products favor its again becom- 

 ing destructive. Forest insects can thus be easily kept under control 

 by good management. 



The desired control or prevention of loss can often be brought 

 about by the adoption or adjustment of those requisite details in for- 

 est management and in lumbering and manufacturing operations, 

 storing, transportation, and utilization of the products which at the 

 least expenditure will cause the necessary reduction of the injurious 



