2 BULLETIN 1400, U. S. DEPARTMENT OF AGRICULTURE 



because the wood has pinholes in it and hence is not suitable for 

 high-grade cooperage or airplane stock, the loss is greater, but per- 

 haps more intangible. Where such timber is accessible and there 

 are suitable markets, it need not be an entire loss, but could be used 

 for lower-grade products. Closer utilization is of prime impor- 

 tance in the prevention of waste in the conservation of our forest 

 resources. 



Better methods of manufacture and the use of forest products, 

 and the elimination of waste, as advocated by the Federal Forest 

 Products Laboratory at Madison, Wis., and the Bureau of Stand- 

 ards of the Department of Commerce, will go far in helping to 

 relieve the great timber' shortage, which is especially serious in the 

 case of the hardwoods. 



The purpose of this bulletin is briefly to describe and illustrate, 

 from the viewpoint of the entomologist, for the benefit of graders, 

 inspectors, manufacturers, or utilizers of timber products, the prin- 

 cipal types of defects in timber caused by insects, the causes of these 

 defects, and, where possible, the mode of applying recommended 

 methods to prevent the damage and loss. The Forest Service has 

 already published a circular on grading lumber (39). 1 



Wood-boring insects not only destroy a considerable quantity of 

 forest products, but also cause the loss of the labor expended during 

 the process of their manufacture. The trees from which these prod- 

 ucts were cut are a loss, and additional trees must be taken from 

 the forest to replace them. To this loss must be added percentages 

 of the cost and upkeep of lumber camps, machinery, equipment, 

 logging railroads, wages and keep of men and animals in the woods, 

 storage in the mill pond, sawing, drying, finishing, and piling at 

 the mill. 



The direct money loss caused by insects to cut timber and lumber 

 assumes an enormous aggregate — greater proportionately than that 

 caused by insects to living timber. To the money loss of production 

 costs must be added the loss of time necessary to properly season the 

 wood. 



Of course, damage to seasoned finished wood products causes 

 relatively greater loss than does damage to crude forest products. 

 Where the products are damaged after being put in place, the cost 

 of replacement involves additional loss of labor and time, as well 

 as the cost of the original and replaced products, a loss far greater 

 than the value of the raw products. Often such replacement charges 

 should be charged to both wood-destroying fungi and wood-boring 

 insects and not to one agency alone, as frequently there is a close 

 relationship between these forms of life in the destruction of timber. 

 However, in many cases wood-destroying fungi alone are responsible 

 for the destruction. 



It has been demonstrated in practice that a large percentage of the 

 $45,000,000 annual loss (43) caused by wood-boring insects in the 

 past can be prevented in the future. The increased prices of lumber 

 and all other forest products make it even more essential that all 

 avoidable waste caused by insect defects should be eliminated in the 

 interest of conservation. 



1 Reference is made by italic numbers in parentheses to " Literature cited," page 44. 



