398 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 



places, such as the trunks and stumps of recently felled or dying oak, 

 maple, apple, and other hardwood or deciduous trees; lumber yards, 



sawmills, freshly cut cordwood from 

 living or dead trees, and forests of 

 hardwood timber. Under such con- 

 ditions the beetles occur in great 

 numbers, and, if the storerooms and 

 cellars in which the barrels are kept 

 are damp, poorly ventilated, and 

 readily accessible to them, serious 

 injury is almost certain to follow. 



TANBARK. Favorable conditions 

 for insect attack and injury to tan- 

 bark (figs. 55 and 56) are found in 

 that which is over three years old 

 from the time it is taken from the 

 tree. This suggests at once a simple 

 and practical method of preventing 

 losses that of labeling the different 

 lots, or piles, with the year the bark 

 was peeled, and then utilizing it be- 

 fore it is old enough to be in danger 

 of attack. While it is a common 

 practice for tanners and dealers to 

 keep a record of the age for other 

 reasons, the utilization of the bark 

 within three years is by no means 

 universal, as was demonstrated by 

 the writer's investigation at one tan- 

 nery, where $50,000 to $75,000 worth 

 of old hemlock bark was found to 

 have been rendered almost worthless, while the remainder of the bark 

 in the yards, which was less than three } 7 ears old, showed no damage 

 whatever. 



FIG. 56. Work of round-headed borer, Phy- 

 matodes variabilis, in oak tanbark: o, 

 adult. (Original. ) 



