CIRCULAR No. 128. 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 ys wy HopPkKINS, 
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 
eut from logs which had been previously infested. They also con- 
4 Revised extracts from Bulletin No. 58, Part V, Bureau of Entomology, U. 8. 
Department of Agriculture, 1909, 
64135°—Cir. 128—10 1 
