2 BULLETIN" 255, U. S. DEPARTMENT OF AGRICULTURE. 



of pitch seams in the logs used. But all Douglas fir sawyers esti- 

 mated a general loss in the entire Douglas fir product of between 

 7.5 and 15 per cent due to this defect. The depreciation is lowest in 

 the Rocky Mountain region and heaviest toward the coast, evidently 

 corresponding to the respectively slower or quicker growth of the 

 trees in the respective localities and to the relative scarcity or 

 abundance of the moth in these regions. 



The writer and his field assistants made a thorough investigation 

 of the logs in the woods and during the sawing of them in the mill, 

 from the manager of which the estimate of lowest loss was received. 

 This mill cuts usually not less than 25,000,000 board feet annually, 

 but the cut during the season 1913-14 was only 14,000,000 board feet. 

 This investigation showed that from 15 to 25 per cent of all the logs 

 in the 14,000,000 board feet had been damaged by the moth. Of the 

 logs clean of branches, in which this sort of damage mainly prevails, 

 fully two-thirds were depreciated in this manner, notwithstanding 

 the fact that those from exposed localities, which are unfavorable to 

 the insect, were practically free from the defect. 



The results of the investigation were taken up with the mill 

 manager and it was agreed that the loss in this case constituted but 

 5 per cent. Yet even this low percentage represented, at the selling 

 price of the lumber at the mill, a loss for that season's low cut of 

 $18,900 to that firm alone. While this percentage is evidently much 

 below the average, it is indicative of what this leak probably means 

 to mills in the entire range of the Douglas fir. 



MANUFACTURERS 1 BEAR THE LOSS. 



At the present selling price the loss is almost entirely borne by the 

 manufacturer. In the absence of the depreciation, consumers could 

 get the best grades of lumber for the prices they now pay for the 

 cheaper grades, and the manufacturers would besides be able to make 

 a larger clear profit, as they would not have to handle the inferior 

 material from the stump to the lumberyard. There is no help for 

 the lumber now being cut, but the defect is avoidable in the future 

 timber supply. There seems to be no reason, therefore, why the cause 

 should not be eliminated and why mills and lumber consumers should 

 be taxed forever by an insect the work of which involves such exten- 

 sive financial waste. 



SCOPE OF THE INVESTIGATION. 



Evidently nothing was known in regard to the larval stages and ac- 

 tivities of this insect until the spring of 1913, when, under assignment 

 from Dr. A. D. Hopkins, the writer undertook a systematic study of 



1 By the term " manufacturer " is meant the " saw-mill " man, and by the term " con- 

 sumer " is meant " contractor, buyer, and builder." A. D. H. 



