Circular No. 1 28. issued December 8, 1910. 



United States Department of Agriculture, 



BUREAU OF ENTOMOLOGY. 

 L. O. HOWARD, Entomologist and Chief of Bureau. 



INSECT INJURIES TO FOREST PRODUCTS." 



By A. D. Hopkins, 

 In Charge of Forest Insect Investigations. 



Damage is caused by various species of insects which are attracted 

 by the varying conditions prevailing at different stages during the 

 process of utilizing the forest resources, from the time the trees are 

 felled until the logs are converted into the crude and finished product 

 and until the latter reaches the final consumer, or even after it is 

 placed in the finished article or structure. As a result, additional 

 drains are made on the timber to meet the demand for the higher 

 grades of lumber and for other supplies to replace those injured or 

 destroyed. From the writer's personal investigations of this subject 

 in different sections of the country it is evident that the damage to 

 forest products of various kinds from this cause is far more extensive 

 than is generally recognized. This loss differs from that resulting 

 from insect damage to standing timber in that it represents more 

 directly a loss of money invested in material and labor. 



CRUDE PRODUCTS. 



Roundheaded borers, timber worms, and ambrosia beetles — Round 

 timber with the bark on, such as poles, posts, mine props, saw logs, 

 etc., is subject to serious damage by the same class of insects as those 

 mentioned under injury to the wood of dying and dead trees. The 

 damage is especially severe when material is handled in such a man- 

 ner as to offer favorable conditions for attack, as when the logs are 

 left in the woods on skidways or in millyards for a month or more 

 after they have been cut from the living trees. Under such condi- 

 tions there is often a reduction in value of from 5 to 30 per cent or 

 more, due to wormhole and pinhole defects caused by roundheaded 

 and flatheaded wood-borers and timber beetles. Frequently the 

 insects continue the work in the unseasoned and even dry lumber 

 cut from logs which had been previously infested. They also con- 



<» Revised extracts from Bulletin No. 58, Part V, Bureau of Entomology, U. S. 

 Department of Agriculture, 1909. 



64135° — Clr. 128—10 1 



